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V okviru diplomske naloge sem pregledala znanstveno literaturo za postopke sintez kovinskih kompleksov 6-metoksikinolina z zlatom(I/III) oziroma platino(II). Enake sintezne postopke sem po preizkušenih reakcijah s 6-metoksikinolinom preizkusila še z molekulo dihidrokinidina. Pri tem sem v reakcijah spreminjala reakcijske pogoje in sinteze preizkušala z uporabo različnih topil. Večino reakcij sem opravljala v temi zaradi občutljivosti na svetlobo zlatovih in platinskih soli. Cilj diplomske naloge je bil pripraviti kompleks 6-metoksikinolina ali dihidrokinidina z zlatom oziroma platino brez nečistoč. Sintetizirane produkte sem okarakterizirala z NMR, masno spektrometrijo in rentgensko strukturno analizo. As part of my diploma thesis, I reviewed the scientific literature for the synthesis procedures of metal complexes of 6-methoxyquinoline with gold(I/III) and platinum(II). After the tested reactions with 6-methoxyquinoline, I tried the same synthesis procedures with the dihydroquinidine molecule. While doing that, I changed the reaction conditions in the reactions and tested the syntheses using different solvents. Most of the reactions were preformed in the dark, due to the light sensitivity of gold and platinum salts. The goal of my thesis was to prepare a complex of 6-methoxyquinoline or dihydroquinidine with gold or platinum without impurities. I characterized the synthesized products by NMR, mass spectrometry and X-ray structural analysis.

An analytical methodology based on an O-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine (MQD)-silica hybrid monolithic column was developed for the enantioseparation of 9-fluorenylmethoxycarbonyl (FMOC) derivatized amino acids by nano-liquid chromatography. The mobile phase was optimized including the apparent pH, content of ACN, and concentration of the buffer to obtain a satisfactory enantioresolution performance. 27 FMOC derivatized amino acids including 19 protein and 8 non-protein amino acids were tested, and 19 out of them were enantiomerically discriminated obtaining baseline separation for 11 of them. Analytical characteristics of the method were evaluated for norvaline and tryptophan in terms of linearity, precision, accuracy, limits of detection (LOD) and quantitation (LOQ) showing good performance to be applied to the enantiomeric determination of these amino acids in dietary supplements. LOD and LOQ values were 9.3 and 31 μM for norvaline enantiomers and 7.5 and 25 μM for tryptophan enantiomers, respectively. The contents of d-norvaline and d-tryptophan were below their respective LODs in all the analyzed samples. Quantitation of l-tryptophan and l-norvaline showed good agreement with the labeled contents except for one sample which did not show presence of l-norvaline, contrary to the label indication., Graphical abstract Image 1, Highlights • A method was developed for the enantiomeric separation of amino acids by nano-LC. • A novel quinidine-silica hybrid monolith was employed as chiral column. • 19 protein and non-protein FMOC-amino acids were enantiomerically discriminated. • Analytical characteristics of the developed method were evaluated. • Norvaline and tryptophan were enantiomerically determined in dietary supplements.

An O-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine (MQD)-silica hybrid monolithic column was prepared by a facile "one-step" strategy within a 100 μm I.D. capillary. The influence of the methanol, ethylene glycol and water volume ratio, reaction temperature and time, cetyltrimethylammonium bromide and MQD monomers content and volume ratio of tetramethoxysilane and vinyltrimethoxysilane was investigated to obtain a satisfactory morphology of monolithic columns. The optimized MQD-silica hybrid monolithic column was evaluated in terms of permeability, stability, efficiency, reproducibility, and was characterized by scanning electron microscopy and nano-liquid chromatography. Among the 52 N-derivatized protein and non-protein amino acids, a total of 44 analytes could be baseline enantioseparated using the optimized conditions in either reversed phase mode (RPM) or polar organic phase mode (POM). The results showed that POM (ACN/MeOH/HAc/TEA (60/40/0.055/0.005, v/v/v/v)) offered better performance than RPM (10 mM ammonium acetate/ACN (30/70, v/v) (apparent pH=5.3)) in terms of enantioresolution and efficiency with shorter analysis times.

Endeavor to discover biorational natural products-based insecticides, two series (30) of novel (9S)-acyloxy derivatives of quinidine and dihydroquinidine were prepared and assessed for their insecticidal activity against Mythimna separata in vivo by the leaf-dipping method at 1 mg/mL. Among all the compounds, especially four derivatives exhibited the best insecticidal activity with final mortality rates of 71.4 %, 75.0 %, 71.4 %, and 75.0 %, respectively. Relatively speaking, 9-hydroxy group is well tolerated, and the results showed that after modification of the hydroxy group with an acyloxy group, the insecticidal activity was significantly increased; the configuration at C8/9 position is important for insecticidal activity, and the (9S)-configuration is optimal; modification of the out-ring double bond is acceptable, and hydrogenation of the double bond enhances insecticidal activity. These preliminary results will pave the way for further modification of quinidine in the development of potential new insecticides.

Chinoline alkaloids found in Cinchona bark still play an important role in medicine, for example as antimalarial and antiarrhythmic drugs. For the first time Supercritical Fluid Chromatography has been utilized for their separation. Six respective derivatives (dihydroquinidine, dihydroquinine, quinidine, quinine, cinchonine and cinchonidine) could be resolved in less than 7 min, and three of them quantified in crude plant extracts. The optimum stationary phase showed to be an Acquity UPC2 Torus DEA 1.7 μm column, the mobile phase comprised of CO2, acetonitrile, methanol and diethylamine. Method validation confirmed that the procedure is selective, accurate (recovery rates from 97.2% to 103.7%), precise (intra-day ≤2.2%, inter-day ≤3.0%) and linear (R2 ≥ 0.999); at 275 nm the observed detection limits were always below 2.5 μg/ml. In all of the samples analyzed cinchonine dominated (1.87%–2.30%), followed by quinine and cinchonidine. Their total content ranged from 4.75% to 5.20%. These values are in good agreement with published data, so that due to unmatched speed and environmental friendly character SFC is definitely an excellent alternative for the analysis of these important natural products.

Sharpless Tis report illustrates the application of Asymmetric Sharpless Aminohydroxylation (ASAH) in the stereoselective synthesis of vicinal amino alcohols as important intermediates in the total synthesis of complex molecules and natural products with significant biological activities. The ASHA allows the regio- syn-selective synthesis of 1,2-amino alcohols via reaction of alkenes with salts of N-halosulfonamides, -amides and -carbamates employing osmium tetroxide (OsO4) as an efficient catalyst. In this reaction, chirality is induced via the addition of dihydroquinine- and dihydroquinidine as derived chiral ligands.

Methods are presented to tritiate the plant natural product analogues dihydrocolforsin and dihydroquinidine.

A new method has been developed for the synthesis of 2-​alkylidenequinuclidines based on a silver triflate catalyzed intramol. hydroamination of 4-​(prop-​2-​ynyl)​piperidines. Monosubstituted piperidines reacted less efficiently than cis-​disubstituted piperidines, and the reaction was selective for an alkyne moiety, even in the presence of a vinyl group at the 3-​position. The hydroamination occurred readily with a terminal alkyne, as well as with an internal alkyne bearing an aliph. or arom. group at the terminal carbon atom. Using this silver-​catalyzed cyclization, a short procedure was developed for the relay synthesis of the cinchona alkaloids dihydroquinidine and dihydroquinine.

(+)-(2S,3R)-Piscidic acid was efficiently synthesized with high optical purity (90% e.e.) via Sharpless catalytic asymmetric dihydroxylation of a trisubstituted olefin in only 6 steps from commercially available 4-hydroxyphenylpyruvic acid as the starting material. The reaction proceeded with high optical purity by using the chiral ligands, dihydroquinidine 2,5-diphenyl-4,6-pyrimidinediyl diether or dihydroquinidine 1,4-anthraquinonediyl diether.

On exposure to the potential carcinogen 1,3-butadiene, the major urinary metabolite in humans is N-acetyl-S-(3,4-dihydroxybutyl)cysteine. A novel, stereoselective synthesis of this cysteine–butadiene metabolite has been developed that is suitable for the production of either diastereomer for use in occupational exposure analysis. L-Cysteine and 4-bromo-1-butene are coupled via an SN2 reaction to give the core structure. A Sharpless asymmetric dihydroxylation using the dihydroquinidine (DHQD) ligand provided the terminal 1,2-diol with the 3-hydroxyl group in the R configuration. Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental resource.

UV and circular dichroism spectroscopic measurements showed that the molecular interactions in hexane/ethyl‐acetate solutions between dihydroquinidine tert‐butylcarbamate, used as a model for the quinidine carbamate chiral selector (QD), and 3‐chloro‐1‐phenyl‐propanol are too weak to affect the corresponding spectra of these compounds. The weak interactions between QD and 3‐chloro‐1‐phenyl‐propanol are probably masked by the formation of self‐associated dimeric structures in solution.

The dihydroxylation of terminal aliphatic n-alkenes catalyzed by OsO 4 .(DHQD) 2 PYDZ ((DHQD) 2 -PYDZ = bis(dihydroquinidine)pyridazine) has been computationally studied by the hybrid QM/MM IMOMM-(Becke3LYP:MM3) method. The cases of propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene have been considered. A systematic treatment for the large number of possible conformations of the longer chain alkenes has been defined and applied, leading to the selection of approximately 1700 conformations to be computed. The IMOMM calculations of the transition states formed between these conformations and the catalyst generate enantiomeric excesses that closely resemble the experimental data of related systems, specifically in the preference for the R isomer and in its dependence on the chain length of the substrate. The selectivity increases sharply with the elongation of the short-chain alkenes until a ceiling value is reached, with further elongations having little effect on the enantiomeric excess (ee). These results are rationalized through the partitioning of the total energy of selected conformers, a process that leads to the identification of the most relevant regions of the catalyst and the characterization of the interactions critical for selectivity.

The synthesis and conformational analyses of several 9-N-acylamino(9-deoxy)cinchona alkaloids is presented. Peptides were connected to cinchona alkaloids via a 9-amino group. The synthesis of the new cinchona alkaloid derivatives was performed straightforwardly from 9-amino(9-deoxy)dihydroquinidine via coupling with carboxylic acid chlorides and several dipeptides. Both alkaloid derivatives with the configuration of the corresponding natural product as well as its unnatural epimer were studied. The conformations of the prepared derivatives in solution were determined by NMR spectroscopy. It is shown that the conformation is strongly influenced by the configuration at the 9-position. Chirality 15:127–134, 2003. © 2003 Wiley-Liss, Inc.

A study of the osmium-catalyzed dihydroxylation of various olefins using air as the stoichiometric oxidant is described. Dihydroxylation takes place smoothly at an air pressure of 20 bar, at 50°C and pH 10.4. In the presence of dihydroquinine or dihydroquinidine derivatives (Sharpless ligands) asymmetric dihydroxylations occur with only slightly lower enantioselectivities compared to the classical K 3 [Fe(CN) 6 ] reoxidation system. In the case of stilbene the solvent system is crucial in determining the chemoselectivity of the reaction. The first example of a selective metal catalyzed oxidative cleavage of an olefin with air to give aldehydes is presented.

A new bifunctional ligand capable of promoting various enantioselective catalytic transformations has been prepared by connecting a bis(oxazoline) to dihydroquinidine via a spacer. This ligand has been employed in a one-pot procedure, in which the asymmetric cyclopropanation and dihydroxylation of styrene were accomplished in a sequential fashion with good enantioselectivity.

The osmium-catalyzed dihydroxylation of various olefins using molecular oxygen or air as the stoichiometric oxidant is reported. Aromatic olefins yield the corresponding diols in good to excellent chemoselectivities under optimized pH conditions (pH = 10.4−12.0). Air can be used under moderate pressures (3−9 bar) instead of dioxygen as the reoxidant. By increasing the oxygen content of the solution, it is possible to achieve highly efficient conversion at low catalyst amount (catalyst/substrate = 1:4000). Tri- and tetrasubstituted olefins are oxidized at pH > 11 to give the corresponding 1,2-diols in good to very good yields without requiring the addition of sulfonamides or other hydrolysis agents. Studies of the dihydroxylation of functionalized olefins demonstrate that the reaction conditions tolerate a variety of functional groups. In the presence of dihydroquinine or dihydroquinidine derivatives (Sharpless ligands), asymmetric dihydroxylations occur with lower enantioselectivities than tose of the cla...

A non-aqueous capillary electrophoretic method developed for the enantioseparation of N-protected amino acids has been applied to the investigation of five new quinine and quinidine derivatives as chiral selectors: 1-adamantyl carbamoylated quinine, 3,4-dichlorophenyl carbamoylated quinidine, allyl carbamoylated dihydroquinine, allyl carbamoylated dihydroquinidine and 1-methyl quininium iodide. The composition of the background electrolyte was 12.5 mM ammonia, 100 mM octanoic acid in an ethanol-methanol (60:40 v/v) mixture containing a 10 mM concentration of the chiral selector. Under these conditions, the enantioseparation of a series of various benzoyl, 3,5-dinitrobenzoyl and 3,5-dinitrobenzyloxycarbonyl amino acid derivatives was studied with respect to selectand-selector relationship and enantioselectivity.

Dioxygen is able, under visible irradiation, to promote the high yielding and highly asymmetric dihydroxylation of α-methylstyrene in the presence of catalytic amounts of Os(VI), phthalazine dihydroquinidine chiral ligand [(DHQD) 2 PHAL].

The suprafacial, vicinal addition of a heterocyclic moiety and a hydroxyl group is achieved by the osmium-catalyzed asymmetric aminohydroxylation (AA) of olefins with amino-substituted heterocycles as the nitrogen sources. Amino alcohols are obtained in up to 97 % yield and with up to 99 % ee when a ligand derived from dihydroquinidine (DHQD-L) is used [Eq. (1); R(i) indicates the remaining portion of the heterocycle (Het); H2 O is the O source]. The AA can now be considered as a means to directly introduce complex, biologically relevant substructures to hydrocarbon backbones.

The origin of enantioselectivity in the dihydroxylation of H2CCH(Ph) catalyzed by (DHQD)2PYDZ·OsO4 ((DHQD)2PYDZ = bis(dihydroquinidine)-3,6-pyridazine) is analyzed theoretically by means of hybrid QM/MM calculations with the IMOMM(Becke3LYP:MM3) method. Twelve different possible reaction paths are defined from the three possible regions of entry of the substrate and its four possible orientations and characterized through their respective transition states. The transition state with the lowest energy leads to the R product, in agreement with experimental results. The decomposition of the interaction energy between catalyst and substrate shows how the selectivity is essentially governed by stacking interactions between aromatic rings, with a leading role for the face-to-face interaction between the substrate and one of the quinoline rings of the catalyst.

All four stereoisomers of (2S, 3R)-(+)-piscidic acid were synthesized with high optical purity via Sharpless catalytic asymmetric dihydroxylation of (Z)- and (E)-trisubstituted olefins in 6 steps from (4-hydroxyphenyl)pyruvic acid. The Wittig reaction of methyl (4-hydroxyphenyl)pyruvate with (carbomethoxymethylene)triphenylphosphorane gave (Z)- and (E)-trisubstituted olefins in a 3:1 ratio. After protecting the phenolic hydroxyl group as the tert-butyldimethylsilyl ether, the (Z)-olefin was subjected to asymmetric dihydroxylation by using the chiral ligand, dihydroquinidine 1,4-anthraquinonediyl diether, and the reaction proceeded with 89% e.e. Desilylation and subsequent alkaline hydrolysis gave (2S, 3R)-(+)-piscidic acid. The optical purity was increased to >99% e.e. by recrystallization. The use of dihydroquinine 1,4-anthraquinonediyl diether enable (2R, 3S)-(-)-piscidic acid to be obtained. In the asymmetric dihydroxylation of the (E)-olefin, phthalazine ligands (dihydroquinidine and dihydroquinine 1,...

The first reagent-controlled asymmetric halolactonizations are described. Complexes of I+ with O-acyl- and O-aryldihydroquinidines are used to promote the asymmetric halolactonization of prochiral θ, δ-unsaturated carboxylic acids with low but measurable and reproducible enantioselectivity. Experimental factors affecting the ee's are described. Key words: halocyclization, halogenation, halonium ions, chiral, stereoselective.

Dihydroxylation of methyl ( E )-2,3-dideoxy-4,5:6,8-di- O -isopropylidene- l - xylo -oct-2-ene-4-ulofuranosonate ( 1 ) with osmium tetraoxide took place with high diastereoselectivity to give a 7:1 mixture of methyl 4,5:6,8-di- O -isopropylidene- α - l - glycero - d - galacto - ( 2 ) and - d - ido -oct-4-ulofuranosonate ( 3 ). When 1 was dihydroxylated in the presence of dihydroquinine and dihydroquinidine p -chlorobenzoate, an appreciable increase and decrease, respectively, in the 2 / 3 ratio was observed. Compound 2 was transformed into its 2,3-di- O -methyl derivative 4 which was deisopropylidenated to methyl 2,3-di- O -methyl- α - l - glycero - d - galacto -oct-4-ulopyranosonate ( 5 ) and subsequently degraded to dimethyl 2,3-di- O -methyl-(+)- l -tartrate ( 6 ). On the other hand, compounds 2 and 3 , separately, were isopropylidenated to the corresponding 2,3:4,5:6,8-tri- O -isopropylidene derivatives 7 and 8 , which were reduced with LiAlH 4 to the related 2,3:4,5:6,8-tri- O -isopropylidene- α - l - glycero - d - galacto - ( 9 ) and - d - ido -oct-4-ulofuranose ( 10 ). Finally, compounds 9 and 10 were deisopropylidenated to the corresponding l - glycero - d - galacto - ( 11 ) and l - glycero - d - ido -oct-4-ulose ( 12 ).

Stachysterone C was synthesized from 20-hydroxyecdysone (20-ECD). Sharpless asymmetric dihydroxylation of this rare ecdysteroid using osmium tetroxide and a chiral ligand afforded 24- epi -abutasterone, another rare ecdysteroid, and its C-24 epimer, abutasterone. High diastereomeric excess of the former ecdysteroid was obtained when the chiral ligands dihydroquinidine 1,4-phthalazinediyl diether and dihydroquinidine 2,5-diphenyl-4,6-pyrimidinediyl diether were employed. The two C-24 epimeric ecdysteroids exhibited similar moulting hormone activity in the Musca bioassay. However, they were significantly less active than 20-ECD.

We describe two procedures for the synthesis of primary amines derived from 9-amino(9-deoxy)epi cinchona alkaloids, valuable catalysts used in the asymmetric functionalization of carbonyl compounds. The first approach allows the one-pot 5-g-scale syntheses of four cinchona-based analogs (1, 3, 5 and 7) from the alkaloids quinine (QN), quinidine (QD), dihydroquinine (DHQN) and dihydroquinidine (DHQD), respectively, performed by means of a Mitsunobu reaction to introduce an azide group, followed by reduction and hydrolysis. Demethylation of 1, 3, 5 and 7 with BBr(3) provided direct access to the bifunctional aminocatalysts 2, 4, 6 and 8. A second approach, more convenient for scale-up (tested to a 20-g scale), is also provided. In this second procedure, the azides, formed from the O-mesylated derivatives of QN and QD, are selectively reduced with LiAlH(4) to afford catalysts 1 and 3, whereas hydrogenation (Pd/C) provides 5 and 7. Demethylation of 1, 3, 5 and 7 using an alkylthiolate affords 2, 4, 6 and 8 in a process in which the less-expensive QN and QD are the only starting materials used.

Combination of variable temperature NMR and CD spectroscopy, and molecular mechanics computations shows that dihydroquinidine exists in two conformations , anti, open (80–90%) and syn, closed (10–20%) separated by a barrier of 8.3 kcal/mol in ether solutions .

The base-catalyzed rearrangement of 1-methylindene (1) to 3-methylindene (2) has been studied. The reaction proceeds with substrate enantioselectivity (kinetic resolution) when chiral tertiary amines are used as catalysts. When dihydroquinidine (DHQD) (3

A sensitive, specific, and rapid high-performance liquid chromatographic method with ultraviolet detection for therapeutic drug monitoring of the cardioactive compound quinidine is described. The method uses only 50 microliters of serum, which is extracted into methyl-t-butylether at an alkaline pH and consequently reextracted into dilute hydrochloric acid. Quinidine is separated from quinine, the internal standard, and dihydroquinidine on a reversed phase C18 column. The minimum detectable amount is 1 ng injected on column. The method is both precise and accurate, as shown by the validation data presented, and can also be of use in pharmacokinetic investigations.

The synthesis of a novel soluble polymer-bound ligand DHQD-PHAL-OPEG-OMe and its application in the catalytic asymmetric dihydroxylation (AD) reaction are described. 1,4-Dichlorophthalazine was used as the coupling reagent to connect dihydroquinidine and polyethylene glycol monomethyl ether (MW=5000, Fluka) while providing an aromatic group at the 9-O-position of dihydroquinidine. Enantiomeric excesses for trans-disubstituted olefins in the AD reaction, with K3Fe(CN)6 as secondary oxidant, are up to 98%.

C 20 H 25 BrN 2 O 2 cristallise dans P2 1 avec a=7,236, b=12,386, c=10,909 A, β=95,89°, Z=2; affinement jusqu'a R=0,0384. La chiralite de C(3), C(4), C(8) et C(9) est la meme que celle de la quinidine, qui est S au nouveau centre C(10). Les molecules sont reliees par des axes 2 1 formant des chaines moleculaires avec une liaison hydrogene entre l'atome O du groupement hydroxyle et l'atome N dans le cycle quinoleine. La distance N...O est de 2,844 A

C 20 H 26 N 2 O 2 .1,5H 2 O cristallise dans P2 1 2 1 2 1 avec a=12,358, b=17,631, c=17,686 A, Z=8; affinement jusqu'a R=0,0522. La maille asymetrique contient deux molecules alcaloides et trois molecules d'eau. Les deux molecules independantes possedent des geometries identiques, sauf une chaine desordonnee ethylenique dans la molecule B. Les longueurs et les angles des liaisons ont des valeurs attendues

Osmium catalyzed asymmetric dihydroxylation of alkenes has been reported using dihydroquinidine (DHQD) and dihydroquinine (DHQ) on a polystyrene support. Effect of other oxidants and additives has been examined.

The 22R,23R-homobrassinosteroid analogs are obtained in good yield from the corresponding precursor with a 22E-double bond by osmium-catalyzed asymmetric dihydroxylation using dihydroquinidine 9-O-(9′phenantryl) ether (DHQD PHN) as chiral agent.

Stachysterone C was synthesized from 20-hydroxyecdysone (20-ECD). Sharpless asymmetric dihydroxylation of this rare ecdysteroid using osmium tetroxide and a chiral ligand afforded 24- epi -abutasterone, another rare ecdysteroid, and its C-24 epimer, abutasterone. High diastereomeric excess of the former ecdysteroid was obtained when the chiral ligands dihydroquinidine 1,4-phthalazinediyl diether and dihydroquinidine 2,5-diphenyl-4,6-pyrimidinediyl diether were employed. The two C-24 epimeric ecdysteroids exhibited similar moulting hormone activity in the Musca bioassay. However, they were significantly less active than 20-ECD.

The first reagent-controlled asymmetric halolactonizations are described. Complexes of I+ with O-acyl- and O-aryldihydroquinidines are used to promote the asymmetric halolactonization of prochiral ...

The suprafacial, vicinal addition of a heterocyclic moiety and a hydroxyl group is achieved by the osmium-catalyzed asymmetric aminohydroxylation (AA) of olefins with amino-substituted heterocycles as the nitrogen sources. Amino alcohols are obtained in up to 97 % yield and with up to 99 % ee when a ligand derived from dihydroquinidine (DHQD-L) is used [Eq. (1); R(i) indicates the remaining portion of the heterocycle (Het); H2 O is the O source]. The AA can now be considered as a means to directly introduce complex, biologically relevant substructures to hydrocarbon backbones.

The synthesis of a novel soluble polymer-bound ligand DHQD-PHAL-OPEG-OMe and its application in the catalytic asymmetric dihydroxylation (AD) reaction are described. 1,4-Dichlorophthalazine was used as the coupling reagent to connect dihydroquinidine and polyethylene glycol monomethyl ether (MW=5000, Fluka) while providing an aromatic group at the 9-O-position of dihydroquinidine. Enantiomeric excesses for trans-disubstituted olefins in the AD reaction, with K3Fe(CN)6 as secondary oxidant, are up to 98%.

A new bifunctional ligand capable of promoting various enantioselective catalytic transformations has been prepared by connecting a bis(oxazoline) to dihydroquinidine via a spacer. This ligand has been employed in a one-pot procedure, in which the asymmetric cyclopropanation and dihydroxylation of styrene were accomplished in a sequential fashion with good enantioselectivity.

The 22R,23R-homobrassinosteroid analogs are obtained in good yield from the corresponding precursor with a 22E-double bond by osmium-catalyzed asymmetric dihydroxylation using dihydroquinidine 9-O-(9′phenantryl) ether (DHQD PHN) as chiral agent.

Osmium catalyzed asymmetric dihydroxylation of alkenes has been reported using dihydroquinidine (DHQD) and dihydroquinine (DHQ) on a polystyrene support. Effect of other oxidants and additives has been examined.

Dihydroquinidine and dihydroquinine bisesters of malonic acid, adipic acid and terephthalic acids are used as chiral auxiliaries for osmium tetroxide catalysed asymmetric dihydroxylation of alkenes. Highly stereoselective osmylation of alkenes has been rationalized on the basis of π-π interaction of the alkenes with the ligand.

Catalytic asymmetric dihydroxylations of 1,3-enynes were studied using 9-O-(9′-phenanthryl) dihydroquinidine (PHN-DHQD) 1 and 1,4-bis-(9-O-dihydroquinidine) phthalazine (DHQD2-PHAL) 2. Terminal olefins showed moderate (38-79% ee) and trans-disubstituted olefins high enantioselectivities (73 – 97% ee).

Double asymmetric induction has been used to increase the diastereoselectivity of the dihydroxylation of the allylsilane +(11) using dihydroquinidine p-chlorobenzoate as catalyst.