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N,N′-Diisopropyl-substituted 1,3,4-oxadiazolidine3c, 1,3,4-thiadiazolidine6, 4,5-benzo-1,2,3,6-tetrahydropyridazine8, and new 3,4-dialkyl-1,3,4-oxadiazolidines9–14 were synthesized and studied. The configurational stability of the N atoms does not change on going from compound3c to itsS-analog6 and decreases in the case of pyridazine8. 3,4-Di-tert-alkyl-1,3,4-oxadiazolidines3d and11–14 were found to be promising objectes for optical resolution.

The title adduct (1) was synthesized, and its conformationally and configurationally rigid chiral structure in solution and in the crystal was established by NMR spectroscopy and by X-ray structural analysis. Atropoenantiomers of1 were observed by the1H NMR method in the presence of a chiral shift reagent. A barrier to their interconversion was determined, ΔGx > Z5 kcal mol−1 (200 °C).

Complete autoassembly of dilactones4–6 from dihydroxytetraesters of the type X2YC(CH2) n CYX2 (X = CO2R, Y = OH,n = 2, 3) was performed in high yields under the conditions of acid or base catalysis. The classic syntheses of the Troger's base, Meerwein ester, and dilactams were considered from the viewpoint of bicycle autoassembly.

Treatment of alkylenebismalonates with NaH and benzoyl peroxide afforded dibenzoyloxy derivatives. Alkaline hydrolysis of the latter gave alkylenebistartronic acids. Tetramethyl and tetraethyl esters and tetraamides of these acids were synthesized

The reactions of aziridine, its dimer, 2,2-dimethylaziridine dimer, and the novel compound β,β-bis-N-aziridinoethylamine with aromatic aldehydes and dialdehydes have given novel compounds.

The conformations of the cis and trans isomers of N-substituted 2,5-dimethyl-4-piperidinones were studied by means of the1H and13C NMR parameters. It was established that in the case of bulky and electron-acceptor substituents attached to the N atom the cis isomers are virtually completely represented by the chair (2a,5e) conformation, while the trans isomers are characterized by the chair (2e,5e) ⇄ twistboat (2a,5e) ⇄ chair (2a,5a) conformational equilibrium. It is demonstrated that 1-tert-butyltrans-2,5-dimethyl-4-piperidinone hydrochloride has the twist (2a,5e) conformation.

Condensation of monoethanolamine with formaldehyde affords 1,6-diaza-3,8-dioxabicyclo[4.4.1]undecane andN,N′-methylene-bis(oxazolidine) in a ratio of 1∶8.

The reaction of secondary phosphines with sulfonyl chlorides gives sulfenylphosphine oxides (esters of dialkylthiolphosphinic acids), and not sulfonylphosphines.

1. The arguments for the phosphonium-phosphorane equilibrium involving the formation of a tricyclic phosphorane previously proposed for phosphonium salt cations R3\(\mathop P\limits^ +\)CH2X (X=R2N, RO, HO, RS), were examined. This proposal was rejected in light of a) the observed nonequivalence of the isopropyl group methyl protons of [i-Pr2(Me)\(\mathop P\limits^ +\)CH2N(CH2CH2)2O] I− in its PMR spectrum in C5D5N solution, b) x-ray structural analysis of this salt (N⋯P distance 2.69(2) A), and c) the configurational stability of [o-MeOC6H4\(\mathop P\limits^ \oplus\)(Me)Pr2-i] I⊖ Up to 190°C. 2. Aminomethylphosphonium salts have aminomethylating action relative to MeO⊖, while phosphineomethylammonium salts do not react with Me.

1. Methods for the aminomethylation of phosphines with alkoxymethylamines and diaminomethanes were developed. 2. Aminomethyl derivatives of asymmetric phosphines and optically active C-chiral and diastereomeric C- and P-chiral aminomethylphosphines were prepared. 3. An enatiomerically enriched (−)-dimethylaminomethyl-tert-butylphenylphosphine, with an asymmetric center at the P atom was synthesized.

1. The IR and Raman spectra of MeCOPMe2, MeCOP(i-C3H7)2, MeCOP(t-C4H9)2, and Me3CCOP(t-C4Hg9)2 in the liquid phase have been studied and interpreted. The normal vibrations of the CC(O)PC2 skeleton have been analyzed. 2. The force constant for the CO bond is significantly lower in the acylphosphines than in acetone. 3. In the liquid phase, the acylphosphines each exist as a single conformer with one plane of symmetry.

1. In contrast to the case of cyanoacetylene, the nucleophilic addition to methyl propiolate takes place with the preferential or exclusive formation of trans products, if steri cally hindered N-nucleophiles and N-, P-, S-nucleophiles with a weakened +M-effect of the central heteroatom are used. 2. For the qualitative evaluation of the stereochemical result of the nucleophilic addition reaction to activated acetylenes, it was proposed to use the σR constant of the activating substituent.

1. The principle of the stereocontrolled assembly of framework structures was confirmed for the case of the synthesis of bicyclic compounds with high yields under mild conditions from derivatives of d,l-α,α′-dihydroxy-α,α′-dimethyl- and threo-α,α′-dihydroxy-α-methyl-α′-ethylglutaric acids. 2. The conformation of the five-membered heterocycles in the derivatives of d,l- and meso-α,α′-dihydroxy-α,α′-dimethylglutaric acid and threo- and erythro-α,α′-dihydroxy-α-methyl-α′-ethylglutaric acids was studied. For the former it was shown that the functional groups have the a,a orientation, which favors secondary cyclization. On this basis the general principle of conformational control during the assembly of bicyclic systems from the monocyclic precursors was formulated. In the derivatives of the meso and erythro series the conformation of the ring changes with increase in the size of the substituent from a-CN to e-COOH and e-COOR. 3. It was shown that the products previously described as biscyanohydrins of acetylacetone and propionylacetone have the iminolactone structure.

An electron diffraction study of the MeC(O)PMe 2 molecule has been carried out which shows that the bond configuration at phosphorus in this compound is flattened from that observed in methylphosphines and dimethylcyanophosphine. This finding, as well as some lowering of barriers to inversion at phosphorus in acylphosphines, may be attributed to a contribution from conjugation of the amide type. Two models with different angles of rotation of the acetyl group about the PC A c bond, ψ, are consistent with the experimental data, those with ψ of 5.7 ± 6.6° (model I) and 78.8± 12.0° (model II) (ψ is measured relative to the C s conformation with the C Me PC Me bisector being cis with respect to the CO bond). Other parameters of the two models agree within uncertainties represented by three times standard deviation values 3σ (distances, r a , in nm; angles in degrees): model I model II PC (average) 0.1863(2) 0.1862(2) CC 0.1536(9) 0.1540(9) CO 0.1219(4) 0.1218(3) CH 0.1094(6) 0.1094(6) C Me PC Me 105.7 (0.9) 105.1 (3.3) C Me PC Me 99.3 (2.0) 102.2 (7.5) PCO 123.0 (0.6) 121.9 (0.6) PCC 115.3 (0.9) 112.7 (0.9) The greater errors for phosphorus valence angles and the angle of rotation, ψ, in the case of model II are due to high correlation between these para A possible difference between the PC Me and PC Ac bond lengths has been estimated to be. ± 0.001nm(model I) or ± 0.003 nm(model II). Neither of the models can be preferred on the basis of the electron diffraction data; the results'obtained are also compatible with' the suggestion of large amplitude torsion motions.

A new type of amine fragmentation under electron impact is elucidated for proline, sarcosine and aspartic acid derivatives and aminomethylphosphines of the general formula R2NCH2X. Ordinary α-cleavage affording the ion is suppressed by elimination of a neutral HX particle and [M - HX]+ ion formation, or M-HX neutral particle ejection and generation of an [HX]+ ion from [M]+˙. Such fragmentation is ensured by the presence of an α-heteroatom (N, O, P, S) in one substituent (X) and a CO2R type delocalizing group in the α-position of the other substituent (R2N).

1. Aziridines and diaziridines give with acetylenes containing two activating substituents X, either predominantly or to a large extent the Z-adducts when X=CN or CF3, and the E-isomers only when X=CO2Me. 2. Dimethyl acetylenedicarboxylate gives with ethyleneimine the 2,2-bis-adduct, and with 1,2,4-triazole, the 2,3-bis-adduct.

1. An efficient method of aziridine dimer synthesis is presented involving reaction of aziridine with esters of strong organic acids followed by alkaline hydrolysis of the resultant N-acyl derivatives. 2. New N-acyl and carbamoyl derivatives of aziridine dimer and trimer were synthesized. 3. Linear and branched isomers of aziridine tetramer and also diastereomers of 2-methylaziridine dimer were isolated and characterized. 4. An efficient regiospecific synthesis of 2,2-dimethylaziridine dimer and trimer was developed.

1. High trans-stereospecificity has been shown in the addition to cyanoacetylene of: a) secondary aliphatic amines, with cooling, and b) under the usual conditions with sterically hindered amines, phosphines, mercaptan, and arsine, and also with amines with reduced positive mesomeric capacity of the nitrogen atom. 2. The cis-products of the addition to cyanoacetylene of aziridines, diaziridine, imidazole, di-tert-butylamine, phosphines, and arsine are highly resistant to cis-trans isomerization. In cis-β-di-tert-butylaminoacrylonitrile, amide-type conjugation is sterically hindered.

New data have been obtained confirming distinct differences in fragmentation of compounds of trivalent nitrogen and other group V elements under electron impact. These data have been obtained for the fragmentation of the cyanamides, cyanphosphines and cyanarsines, as well as of their vinylogues.

X-ray diffraction and NMR spectral examination have shown that 1-phenyl-3-methyl-2-pyrazolin-5-one reacts with methyl acrylate in methanol to give spiro[(1-phenyl-3-methyl-2-pyrazolin-5-one)-4,5′-butyrolactone]. The conformation has been shown to be the same in the crystal and in solution, the pyrazoline ring has been found to be nonplanar, the reasons for the acoplanarity established, stabilizing and destabilizing interactions studied, and the orientation of the phenyl substituent relative to the pyrazolin-5-one ring determined.

A linear correlation was obtained between the barriers to pyramidal inversion of the phosphorus and the31P chemical shifts of acyldiisopropylphosphines. It was shown that it can be applied to various acyl-, diacyl-, triacyl-, and cyanophosphines if the increments of the31P chemical shifts of the substituents are taken into account.

1. The automatic assembly of dilactones from α,α′-dihydroxyglutaric acids and their derivatives is controlled not only by configuration (from the d, l and not the meso form) but also by conformation and is not realized in the presence of α,α′-substituents having predominantly pseudoequatorial orientation in the corresponding monolactone. Thus, γ-crotonolactone is formed instead of the expected dilactone during the thermolysis of d,l-α,α′-dihydroxyglutaric acid. 2. The diastereomers of α,α′-dibromoglutaric acid and the d,l-forms (in contrast to the meso form) of α,α′-dihydroxyglutaric acid and their esters are conformationally uniform in the case where there is no intramolecular hydrogen bond. 3. The meso forms of the conformationally uniform α,α′-disubstituted glutaric acids differ from the d,l-forms in the nonequivalence of the JCH spin-spin coupling constants with the protons of the CH2 group. 4. Pseudoaxial preference was detected for the CO2H and CO2Me groups in trans-2-hydroxy-4-carboxy-γ-butyrolactone and its methyl ester respectively.

It was shown that the stereospecificity of SSCC3 C,H trans > 3J C,H cis is applicable as a configurational test for di- and trisubstituted alkenes R2E(Y)C=C(X)H with various heteroatomic substituents (E=N, P, S) and activating groups (X=CO2Alk, CN at Y=H, and X=Y=CO2Alk, CN, CF3).

1. The unsymmetrical secondary phosphines were synthesized: isopropylbenzylphosphine and tertbutylbenzylphosphine. 2. Treatment with ketenes or carboxylic acid chlorides gave a number of acyl derivatives of primary phosphines, of symmetrical and unsymmetrical secondary phosphines, and also of diisopropylarsine. 3. The parameters of the NMR spectra were measured for a number of simple phosphines, diisopropylarsine, and also the chloro and acyl derivatives.

Further investigations have given new data confirming differences in fragmentation under electrol impact of compounds of trivalent nitrogen and other group V elements. These data have been obtained by comparision of the fragmentation of the amines, phosphines, arsines, benzyl derivatives, geminal systems and acyl derivatives. Mass spectra of tetraethyl derivatives of the group IV elements and acetyl triethyl germane have also been taken and compared with the previous ones.

Distinct differences are observed on comparison of the fragmentation of tertiary amides (I to XI), and acylphosphines (XII to XVII) and (XX to XXII) under electron-impact, as well as of their vinylogues (XXIII to XXXI) and (XXXIV to XXXV).