R. G. Kostyanovsky

Single-stage synthesis of 3-hydroxy- and 3-alkoxy-5-arylimidazolidine-2,4-diones by reaction of arylglyoxal hydrates with N -hydroxy- and N -alkoxyureas

n Arylglyoxal hydrates interact with N-alkoxyureas and N-hydroxyurea in acetic acid with selective formation of 3-alkoxy-5-arylimidazolidine-2,4-diones and 5-aryl-3-hydroxyimidazolidine-2,4-diones, respectively. The structures of 3-methoxy-5-phenylimidazolidine-2,4-dione, 3-ethoxy-5-phenylimidazolidine-2,4-dione, and 3-butoxy-5-(4-chlorophenyl)imidazolidine-2,4-dione were studied by X-ray structural analysis.

Cyclic hydroxamic acids derived from α-amino acids 2. Regioselective synthesis, crystal structure, and antitumor activity of spiropiperidine- imidazolidine hydroxamic acids based on glycine and dl-alanine

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.

Geminal systems: 64. N-alkoxy-N-chloroureas and N,N-dialkoxyureas

Molecular and crystal structures of N-alkoxy-N-chloroureas and N,N-dialkoxyureas were studied together with those of N-alkoxyureas as reference compounds. N-Alkoxy-N-chloroureas were found to have an elongated N—Cl bond and a shortened N–O(Alk) bond due to the nO(Alk)→σ*N–Cl anomeric effect. Alcoholysis of N-alkoxy-N-chloro derivatives of urea, N′-arylureas, and carbamates in the presence of silver trifluoroacetate leads to sterically hindered N,N-dialkoxyureas, N,N-dialkoxy-N′-arylureas, and N,N-dialkoxycarbamates, respectively.

Novel 1,10-diaza-18-crown-6 derivatives

Reaction of 1,10-bis(methoxymethyl)-1,10-diaza-18-crown-6 (1) with trimethylsilyl azide resulted in hitherto unknown 1,10-bis(azidomethyl)-1,10-diaza-18-crown-6 (2) and novel ionic compound 1,10-bis(azide anion)-1,10-dihydro-1,10-diaza-18-crown-6 (3). Compound 2 rnneacted with dimethyl acetylenedicarboxylate to give 1,10-bis(4,5-dimethoxycarbonyltriazolomethyl)-1,10-diaza-18-crown-6 (4). Carbamoylation of 1,10-diaza-18-crown-6 (5) with optically active α-phenylethyl amine yielded optically active 1,10-bis(α-phenylethylcarbamoyl)-1,10-diaza-18-crown-6 (6).

2-Carbamoylaziridine (Leakadine): diastereoselective transformations and stereoelectronic effect*

Diastereoselective transformations of Leakadine were discovered: dimerization during melting or heating in CHCl3 with the formation of one diastereomer. The obtained dimer reacts with methyl isocyanate under mild conditions with the formation of an N-methylcarbamoyl derivative – also in the form of one diastereomer. In the diastereoselective reaction of Leakadine with dimethyl formamide dimethyl acetal, 2-dimethylamino-1,3-diazabicyclo[3.1.0]hexan-4-one was obtained. The reaction of Leakadine with perfluoroisobutylene was studied.

Synthesis of chiral glycolurils from (S)-(+)- and (R)-(-)-1-sec-butyl-3-methylurea

Chiral dialkyl- and tetraalkylglycolurils have been obtained using chiral (S)-(+)- and (R)-(-)-1-sec-butyl-3-methylurea as starting materials. The diastereomer (S)-(+)-2,6-di-sec-butyl-4,8-dimethyl-2,4,6,8-tetraazabicyclo[3.3.0]-octane-3,7-dione was separated into stereoisomers, for the higher melting of which the absolute configuration was determined as (S,S,S,S) by X-ray structural analysis.

Atropoenantiomerism of the Z-adduct of 2,3-diethoxycarbonyi-6,6-dimethyl-5,6-dihydro-4-pyridone with dimethyl acetylenedicarboxylate: synthesis and structure in solution and in the crystal

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 interconversïon was determined, ΔGx > Z5 kcal mol−1 (200 °C).

Autoassembly of cage structures: 9. Complete autoassembly of dilactones of ?,??-dihydroxy-?,??-dialkoxycarbonyladipic and -pimelic acids

Complete autoassembly of dilactones4–6 from dihydroxytetraesters of the type X2YC(CH2)nCYX2 (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 Trögers base, Meerwein ester, and dilactams were considered from the viewpoint of bicycle autoassembly.

Self-assembly of frame structures. 10. Stereochemistry of 2,5-dioxabicyclo [2.2.1]heptane-3,6-digne

By optimization of the geometry of 2, 5-dioxabicyclo[2. 2.1]heptane-3.6-dione (1) with an ab initio (RHF/6-31 G) calculation, we have found that a single synchro(+, +)-twist form (A) corresponds to the (1 R,4R)-enantiomer (the dihedral angles of the lactone bridges areϕ0 = 2.6°). According to MM2(91) and MM3(92) calculations, (1R,4R)-1 exists as the s-ynchro(+, +)-A-twist (ϕ0 = 3.9°) and the synchro(-, -)-B-twist (ϕ = -3.8°) forms, respectively. Investigating the torsional energy surface of the dilactone 1 (MM2(91)), we found only the (1R,4R,P)-diastereomeric form (A), which is stabilized compared with the (1R,4P,M) form (B) (probably as a result of the more preferred dipole-dipole interaction of the carbonyl groups). According to the calculated puckering coordinates, the five-membered and six-membered moieties of the bicycle 1 are flattened compared with norbornane.