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Regioselective cyclocondensation of glycine hydroxamic and dl-alanine hydroxamic acids with 1-methylpiperidin-4-one gave 1-hydroxy-8-methyl-1,4,8-triazaspiro[4.5]decan-2-one (5) and (±)-1-hydroxy-3,8-dimethyl-1,4,8-triazaspiro[4.5]decan-2-one (6), respectively. The X-ray diffraction data showed that acid 6 formed racemic crystals with two independent molecules, whose structure was studied and compared with the analog obtained earlier. The in vivo tests on the leukemia P388 and L1210 models showed that the low-toxic spirocyclic hydroxamic acids 5 and 6 were the adjuvants of clinic cytostatics cisplatin and cyclophosphamide. Chemotherapy of the leukemias P388 and L1210 was more efficient with the combination of acid 6 with cisplatin and cyclophosphamide, respectively.

A new heterocyclic compound, 3-methyl-5-trinitromethyltetrazolo[1,5-a]-1,3,5-triazin-7-one, was synthesized by the reaction of methyl iodide and the silver salt of 5-trinitromethyltetrazolo[1,5-a]-1,3,5-triazin-7-one. An X-ray diffraction structural analysis of this product was carried out and feasibility was demonstrated for the nucleophilic substitution of the trinitromethyl group in this compound by the action of phenol, phenol derivatives, and thiophenol.

An X-ray single crystal study of C-(4-methoxy-1-vinyl)-N-phenyl nitron (1) and C-(4-methoxy-1-vinyl)-N-bromphenyl nitron (2) was undertaken. The main crystal data: (1): C16H15NO2, a = 8.402(5) A b = 5.408(3) A, c= 14.554(7)A, β= 93.1 (2)°, d cal.= 1.273 g/cm3, V cal.=660.3 (2)A3, Z= 2, Sp.gr.Pc. M= 253.32: (2):C16H14NO2Br, a= 17.586(6)A, b= 14.543(5)A, c= 5.632(4)A, α=89.8(2)°, β,=90.8(2)°, γ= 98.9(2)°, d cal.= 1.554g/cm3, V cal.= 1423.0(2)A, Z= 4, Sp. gr. P1, M= 332.21 Compound 2, as distinct from 1, crystallizes in the form of two independent molecules. Molecules of 1 and 2 are nonplanar and have similar conformations. The photoconversion connected with the closing of the oxaziridine heterocycle was computer simulated and its possibility proved for crystals of 1 and 2 using the calculation of the unit cell free volume portion and the difference in the volumes of the initial and final molecules.

An X-ray study of the crystals of C−(2-phenoxy-1-vinyl)-N-n−bromophenyl nitrone (I) and C−(2-phenoxy-1-vinyl)-N−phenyl nitrone (II) has been performed. The main crystal data of I: C15H12NO2Br, a=10.807(5) A, b=10.275(5)A, c= 15.415(7)A, β=129.7(2)°, M = 318.14, V= 1525(2)A3, d calc = 1.3S5(3)g/cm3, Space gr. P21/b, Z= 4. The main crystal data of II: C15H13NO2, a = 12.760(4)A, b = 19.784(6) A, c = 9.805(4) A, M = 239.64, V = 2475(1) A3, d calc = 1.284(2) g/cm3, Space gr. Pbna, Z = 8. The crystal packing of I and II is characterized by the presence of centrosymmetric dimer associates (CDA) existing due to stable intermolecular hydrogen bonds (IMHB). Such a crystalline structure of these nitrones accounts for the possibility of intermolecular proton transfer along the O → O coordinate to form a coloured quinoid product.

Hydrocyanation of 3-methylpentane-2,4-dione stereospecifically gave trans,trans-iminolactone 1, whose configuration was established by X-ray diffraction of the corresponding lactone 2; the rate of cyclization of the diastereoisomeric lactonic acids 3a,b and their esters 4a,b into dilactone 5 was controlled sterically by the methyl groups with cis,cis-isomers 3b, 4b predominating; alcoholysis of 5 regiospecifically afforded ester 4b.

The title dilactone has been resolved into its enantiomers (+)- (S,S)-1 and (–)-(R,R)- 1, whose absolute configurations were found by X-ray diffraction analysis of intermediate lactonic amide 2a; the magnitude of the n–π* Cotton effect increased with an increase in folding or a diminution in twist of the boat conformation of a dilactone ring.

Hydrocyanation of 3-methylpentane-2,4-dione stereospecifically gave trans,trans-iminolactone 1, whose configuration was established by X-ray diffraction of the corresponding lactone 2; the rate of cyclization of the diastereoisomeric lactonic acids 3a,b and their esters 4a,b into dilactone 5 was controlled sterically by the methyl groups with cis,cis-isomers 3b, 4b predominating; alcoholysis of 5 regiospecifically afforded ester 4b.