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Abstract: A stereoselective synthesis of tetrahydropyran–tetrahydrofuran (THP–THF) core 2 of (+)-muconin (1) has been achieved using Prins cyclization as a key step to construct tetrahydropyran moiety. Other important transformations such as Wittig olefination, Sharpless epoxidation, regio-, and stereoselective exo-cyclization of the epoxy alcohol, titanocene induced regioselective deoxygenation of 2,3-epoxy alcohol, Grignard reaction, and Barton–McCombie reaction are successfully employed to accomplish the synthesis of THP–THF core 2. [Copyright &y& Elsevier]

Abstract: Stereoselective synthesis of the C21–C40 core segment of caylobolide A has been achieved following a highly efficient convergent strategy. The key reactions featured in the synthesis are Prins cyclization, reductive radical cyclization, Sharpless asymmetric epoxidation and olefin cross metathesis. [Copyright &y& Elsevier]

Abstract: The stereoselective total synthesis of (−)-brevisamide, a novel marine cyclic ether alkaloid isolated from dinoflagellate karenia brevis is described. The key steps involved in this synthesis are the Sharpless asymmetric epoxidation and regioselective ring opening of chiral epoxide by Gilman's reagent. The tetrahydropyran core has been constructed by an intramolecular SN2 cyclisation. [Copyright &y& Elsevier]

Abstract: A stereoselective synthesis of fragment A of cryptophycin is achieved utilizing the versatile Prins cyclization. Subsequently, the total synthesis of cryptophycin-24 (arenastatin A) has been accomplished by coupling it with the depsipeptide subunit. [Copyright &y& Elsevier]

Abstract: (R)-Citronellal undergoes initial ene reaction followed by Prins cyclization with aldehydes in the presence of 5mol% of scandium triflate at ambient temperature to furnish octahydro-2H-chromen-4-ols in good yields and with high cis-selectivity. The use of scandium triflate makes this procedure simple, more convenient, and practical. [Copyright &y& Elsevier]

Abstract: The reaction of aldehydes with N-tosyl homoallylamine in the presence of a solution of tetrafluoroboric acid-diethyl ether complex in dichloromethane at ambient temperature gave the 4-fluoropiperidines in good yields and with high cis-selectivity. This aza-Prins-type cyclization has a wide scope and the use of HBF4·OEt2 makes this procedure simple, convenient, and cost-effective for the preparation of 4-fluoropiperidines. [Copyright &y& Elsevier]

Abstract: A simple and efficient total synthesis of five-membered pyrrolidine, (+)-pseudohygroline is described. The key steps involved in this synthesis are highly stereoselective Prins cyclisation followed by reductive ring opening and hydroboration. [Copyright &y& Elsevier]

Abstract: The secondary homoallylic alcohol derived from d-glucose undergoes smooth coupling with aldehydes in the presence of molecular iodine under mild reaction conditions to produce 7-iodofurano[3,2-b]pyrans in good yields. This method is highly stereoselective, affording cis-tetrahydropyrans exclusively. [Copyright &y& Elsevier]

Abstract: A facile synthesis of a key intermediate for the total synthesis of anti-mycobacterial compound pseudopteroxazole is described employing an intramolecular Diels–Alder cyclization and an iodine-mediated oxidative aromatization step. [Copyright &y& Elsevier]

Abstract: Aldehyde, homoallylic amine and arene undergo smooth cyclization in the presence of BF3·OEt2 to afford 4-arylpiperidines in good yields and with high trans-selectivity. This is the first report on the preparation of 4-arylpiperidines via aza-Prins-Friedel–Crafts reaction. [Copyright &y& Elsevier]

Abstract: Stereoselective total synthesis of decarestrictine-J, a polyketide natural product is described. The synthesis involves the Prins cyclisation and Ring Closing Metathesis (RCM) as key steps. [Copyright &y& Elsevier]

Abstract: A three-component coupling of aldehyde, homoallylic alcohol and aryl thiol has been achieved in the presence of trifluoroacetic acid in dichloromethane at room temperature to produce 4-arylthiotetrahydropyrans in good yields with all cis-selectivity. This method is simple, selective and convenient for introducing a thiol group on a tetrahydropyran ring. [Copyright &y& Elsevier]

Abstract: 4-Hydroxypiperidines are prepared in good yields and with high selectivity by means of aza-Prins-cyclization using 10mol% phosphomolybdic acid under mild reaction conditions. This is the first report on the preparation of 4-hydroxypiperidines via aza-Prins-cyclization. [Copyright &y& Elsevier]

Abstract: A stereoselective and convergent approach to basiliskamides A and B is achieved through our recently developed strategy for the construction of polyketide precursors via Prins cyclisation. The approach mainly relies upon reductive opening of 1-iodomethyl cyclic ethers, Mitsunobu inversion, Takai olefination and Stille coupling along with Prins cyclisation. [Copyright &y& Elsevier]

Abstract: Homoallylic alcohols, carbonyl compounds and nitriles undergo a smooth tandem Prins–Ritter type cyclization in the presence of CeCl3·7H2O/AcCl at ambient temperature to produce 4-amido tetrahydropyrans in high yields with all cis-selectivity. Spirocyclic 4-amido tetrahydropyrans are obtained in the case of cyclic ketones. [Copyright &y& Elsevier]

Abstract: 1-Butyl-3-methylimidazolium based ionic liquids are found to accelerate significantly the intermolecular 1,3-dipolar cycloaddition of nitrones derived in situ from aldehydes and phenyl hydroxylamine, with electron deficient olefins to afford enhanced rates and improved yields of isoxazolidines with high regio- and diastereoselectivity. [Copyright &y& Elsevier]

Abstract: The stereoselective total synthesis of tarchonanthuslactone, a polyketide natural product, has been achieved. The synthesis exploits the high stereochemical control in the Prins cyclisation along with ring closing metathesis (RCM) as a key step. [Copyright &y& Elsevier]

Stereoselective total synthesis of two chiral lactones, (+)-trans-cognac lactone (1b) and (+)-trans-aerangis lactone (2c), has been achieved from the same intermediate using a radical-based cyclization route. [ABSTRACT FROM AUTHOR]

α,β-Unsaturated aldehydes bearing a δ-hydroxyl group undergo a tandem Michael and intramolecular Friedel–Crafts type cyclization with arylamines in the presence of 5 mol % of Bi(OTf)3 under mild conditions to afford a new class of chiral tetrahydroquinolines in good yields with high stereoselectivity. Structural assignments and the stereochemistry of the products was achieved using various 1D and 2D-NMR experiments. [Copyright &y& Elsevier]

Describes the free radical cyclization of enantiomerically pure alkyne-tethered aldehydes obtained from a carbohydrate. Synthesis of compounds 6 and 7 obtained from a derivative of D-ribose; Absolute configuration at the stereocenter formed during the carbocyclization; Specific transformation of 7-methoxymethoxy-2,2-dimethyl-4-methylene-5-tertbutyldimethylsilyloxy-per hydrobenzo dioxole into optically pure alloquercitol and talo-quercitol.

Abstract: A stereoselective total synthesis of 4-((3S,5R)-3,5-dihydroxynonadecyl)phenol has been accomplished in two different synthetic approaches. In the first approach, Prins cyclization has been successfully utilized to produce the anti-1,3-diol unit, which was further converted into a required syn-1,3-diol through Mitsunobu reaction. The side chain was constructed through cross metathesis and hydrogenation sequence. In the second approach, the chiral syn-1,3-diol was prepared by a sequence of reactions such as alkylation of 1,3-dithane with (R)-epichlorohydrin, ring opening of the epoxide with vinylmagnesium bromide, and 1,3-syn-reduction of the β-hydroxyketone with NaBH4 in the presence of diethylmethoxyborane. [Copyright &y& Elsevier]

Abstract: A convergent and highly stereoselective total synthesis of the Z-isomer of cytospolide E has been achieved via Evan’s aldol reaction, Sharpless kinetic resolution and RCM cyclisation. [Copyright &y& Elsevier]

Abstract: An expedient stereoselective total synthesis of 18-carbon (+)-(6S,9R,10R)-bovidic acid, isolated from the pelage and skin of a gaur B. frontalis is described using l-proline catalysed sequential α-aminoxylation and Horner–Wadsworth–Emmons olefination of aldehyde, cross metathesis and tandem Sharpless asymmetric dihydroxylation-SN2 cyclization reaction as the key steps. [Copyright &y& Elsevier]

Abstract: The synthesis of symmetrical 2,6-disubstituted 4-fluorotetrahydropyran derivatives has been achieved using HBF4·OEt2 via a tandem allylation and Prins cyclization. This is a highly efficient and diastereoselective approach for the preparation of 4-fluorotetrahydropyrans in a single step. The use of readily available and easy to handle reagent HBF4·OEt2 makes this method simple, convenient and practical. [Copyright &y& Elsevier]

Abstract: The silylated secondary homopropargylic alcohols undergo smooth coupling with aldehydes in the presence of molecular iodine under mild reaction conditions to produce 4-iododihydropyrans in good yields. This method is highly stereoselective, affording cis-dihydropyrans exclusively. [Copyright &y& Elsevier]

Abstract: p-Toluenesulfonic acid is found to catalyze the coupling of (Z)-hex-3-ene-1,6-diol with a series of aldehydes by means of intramolecular-Prins-cyclization to provide the corresponding hexahydro-2H-furo[3,2-c]pyran derivatives in good yields with complete cis-selectivity, whereas the coupling of (E)-hex-3-ene-1,6-diol with aliphatic aldehydes gave trans-fused bicyclic furopyrans. [Copyright &y& Elsevier]

Abstract: An efficient stereoselective total synthesis of (−)-pyrenophorol 1 is described. The key steps involved in this synthesis are hydrolytic kinetic resolution (HKR), MacMillan α-hydroxylation, Horner–Wadsworth–Emmons (HWE) reaction, and Mitsunobu cyclization. [Copyright &y& Elsevier]

Abstract: The cyclic 1,3-dicarbonyl compounds undergo smooth cyclization with aryl propargyl alcohols in the presence of 10mol% indium tribromide in refluxing dichloroethane to produce 2,4-diarylpyran derivatives in good yields with high selectivity. [Copyright &y& Elsevier]

Abstract: Epoxides undergo cyclization with homopropargylic alcohols in the presence of zirconium tetrachloride under mild conditions to afford the corresponding dihydropyran derivatives in excellent yields under mild conditions. [Copyright &y& Elsevier]

Abstract: An efficient and flexible approach for the total synthesis of (−)-tetrahydrolipstatin is described. The main features of the synthetic strategy are a stereocontrolled radical cyclization and the successful utilization of commercially available S-malic acid. [Copyright &y& Elsevier]

Abstract: A novel Prins/Friedel–Crafts cyclization of (Z)-6-(1-methyl-1H-indol-3-yl)hex-3-en-1-ol with aldehydes has been achieved using a catalytic amount of BF3·OEt2 under mild reaction conditions to produce the corresponding octahydropyrano[4,3-a]carbazole derivatives in good yields with high diastereoselectivity. The cross-coupling of (Z)-6-(1-methyl-1H-indol-3-yl)hex-3-ene-1-thiol with aldehydes affords the corresponding octahydrothiopyrano[4,3-a]carbazole derivatives under similar conditions. [Copyright &y& Elsevier]

Abstract: A carbohydrate derived synthesis of C16–C29 fragment of sorangicin A is described utilizing regioselective epoxide opening, segment-coupled Prins cyclization reaction and cross metathesis as the key steps. [Copyright &y& Elsevier]

Abstract: Several N-protected homoallyl amines and epoxides were subjected to an aza-Prins cyclization. A rapid and efficient BiCl3 promoted stereoselective synthesis of trans-2,4-disubstituted piperidine derivatives was achieved. [Copyright &y& Elsevier]

The diastereoselective total syntheses of dodoneine (1) and epidodoneine (2) have been accomplished with an overall yield 11.2%. The key steps involved in this approach are Jacobsen hydrolytic kinetic resolution, Prins cyclisation and ring closing metathesis (RCM). The Prins cyclisation has successfully been utilized for the first time to construct ant i-1,3-diols, which are key precursors for dodoneine and its diastereomer, epidodoneine. This approach is highly diastereoselective to generate the required stereocenters of the natural product. To create your abstract, type over the instructions in the template box belowFonts or abstract dimensions should not be changed or altered. Leave this area blank for abstract info.Stereoselective total syntheses of dodoneine and its diastereomer, epidodoneine via Prins cyclisation. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: The homoallylic alcohol tethered with a benzylic hydroxyl group, that is, (E)-4-(2-(hydroxymethyl)phenyl)but-3-en-1-ol undergoes smooth Prins bicyclization with various aldehydes in the presence of 20mol% Sc(OTf)3 and 4Å MS at 80°C to afford a novel series of 1-(tetrahydrofuran-3-yl)-1,3-dihydroisobenzofuran derivatives in good yields with high diastereoselectivity. [Copyright &y& Elsevier]

Abstract: A variety of aldehydes undergo a tandem acetalization and intramolecular Prins cyclization with pent-4-ene-1,2-diol in the presence of 5mol% scandium triflate and 15mol% p-toluenesulfonic acid (TsOH) in dichloroethane at 80°C to produce the corresponding bicyclic ethers, that is, 2,6-dioxabicyclo[3,2,1]octane derivatives in good yields and with high selectivity. The salient features of this methodology are higher yields, lower catalyst loadings, and faster reaction times. The combination of Sc(OTf)3 and TsOH (1:3) was found to be more effective than either Sc(OTf)3 or TsOH alone. [Copyright &y& Elsevier]

Abstract: (2-(4-Methoxyphenyl)-4-methylenetetrahydrofuran-3-yl)methanol reacts smoothly with different aldehydes in the presence of InCl3 at an ambient temperature to afford a novel series of cis-fused 7a,3,6-trisubstituted hexahydro-1H-furo[3,4-c]pyran derivatives in good yields with high selectivity. This is the first Letter on the synthesis of cis-fused hexahydro-1H-furo[3,4-c]pyran derivatives via the Prins cyclization. [Copyright &y& Elsevier]

Abstract: A tandem ene/Prins cyclization of olefin tethered aldehyde with an aldehyde has been accomplished using 5mol% scandium triflate at ambient temperature to afford a novel series of cis-fused octahydropyrano[2,3-c]pyrrole derivatives in good yields with high selectivity. This is the first report on a tandem cyclization of 4-methyl-N-(3-methylbut-2-enyl)-N-(2-oxoethyl)benzenesulfonamide with aldehydes. [Copyright &y& Elsevier]

Abstract: 1,3-Diaryl propargyl alcohols undergo smooth intramolecular Friedel–Crafts cyclization with triethylsilane in the presence of 10mol% iodine 3-aryl-1H-indene derivatives in good yields in short reaction times. This is the first example on the synthesis of substituted indenes from 1,3-diaryl propargyl alcohols. The use of inexpensive and readily available molecular iodine makes this method quite simple, more convenient, and practical. [ABSTRACT FROM AUTHOR]

Abstract: The coupling of (E)- and (Z)-hex-3-ene-1,6-ditosylamide with various aldehydes in the presence of 10mol% Sc(OTf)3 gave the corresponding trans- and cis-fused 1,5-ditosyl-octahydro-1H-pyrrolo[3,2-c]pyridines, respectively, in good yields via intramolecular aza-Prins cyclization, whereas the coupling of (E)- and (Z)-N-(6-hydroxyhex-3-enyl)-4-methylbenzenesulfonamide afforded the corresponding trans- and cis-fused octahydro-1-tosylpyrano[4,3-b]pyrroles derivatives, respectively, via intramolecular Prins-cyclization. [Copyright &y& Elsevier]

Abstract: The Prins-type cyclization of ketones with homoallylic and homopropargylic alcohols in the presence of TMSI generated in situ from TMSCl and NaI produced 2,2-disubstituted- or spirocyclic-4-iodo-tetrahydropyrans and spirocyclic-4-iodo-5,6-dihydro-2H-pyrans in good yields. These iodopyrans are reported for the first time. [Copyright &y& Elsevier]

Abstract: A stereoselective total synthesis of xyolide is described employing MacMillan α-hydroxylation, Steglich esterification, and ring closing metathesis as key steps. The use of organocatalytic MacMillan α-hydroxylation to construct two of the chiral centers of the xyolide makes this approach attractive. [Copyright &y& Elsevier]

Abstract: Ttandem ene-Prins cyclization between an aldehyde and an olefin tethered sugar aldehyde has been achieved using a catalytic amount of scandium triflate (10mol%) at ambient temperature to give a novel series of sugar annulated pyranopyran derivatives in good yields with high selectivity. This is the first report on sugar based ene-Prins cyclization between an aldehyde and O-prenyl derivative of a sugar aldehyde. [Copyright &y& Elsevier]

Abstract: The stereoselective total synthesis of achaetolide 1 has been achieved and its absolute stereochemistry has been reconfirmed to be 3S,6R,7S,9R configuration. Keck allylation, Sharpless asymmetric dihydroxylation, and ring closing metathesis are the key steps involved in the target synthesis. [ABSTRACT FROM AUTHOR]