L. O. Atovmyan

Formation pathways and structure—Property interrelationship of 3-imino-1-methyl-5,5-dialkyl-4,7,7-tricyano-2-oxabicyclo-[2.2.1]heptane derivatives

The problems of the structure—property interrelationship of 3-imino-2-oxabicyclo[2.2.1]heptane derivatives are discussed on the basis of x-ray diffraction studies (XDS). A pathway for the formation of the bicyclic compounds is proposed, and the realization of spirans in the reaction of sym-tetracyanoethane with conjugated cyclic systems containing s-cis C=C and C=O fragments is substantiated. The factors responsible for the syn orientation of the oxygen atom and the N-substituent of the imino group are analyzed. It is shown that a change in the steric hindrance in the bicyclic compounds leads to a change in the conformation of the latter. The reasons for the shortening of the Csp3-Csp3, Csp3-Csp and C=N exo bonds and the correlation of the XDS and IR spectroscopic data are examined. From the XDS data for N-bromo-substituted imines, a model for Br+...N≡C electrophilic attack was proposed

Chemistry of 1,1,2,2-tetracyanoethane. 12. Condensation of 1,1,2,2-tetracyanoethane with crotonaldehyde in alcoholic solution

Conclusions1.Condensation of 1,1,2,2-tetracyanoethane with crotonaldehyde and the solvent (alcoholic medium) takes place in the ratio 1∶2∶1 to give 2-amino-5-methyl-3-(1-methyl-3-alkoxyallyl)-1-formyl-3, 4,4-tricyanoyclopentenes.2.On the basis of an x-ray diffraction analysis of the product with an isopropoxy-group in the 3-position, the main features of its molecular structure are discussed, and a stepwise route is proposed for the reaction and its stereochemical features examined.

Chemistry of 1,1,2,2‐Tetracyanoethane. Part 7. Synthesis and Addition Reactions of Nucleophilic Agents to One of the Cyano Groups of 3‐(N′,N′‐Dimethyl‐N‐acetylhydrazino)‐5‐methyl‐1,1,2,2‐tetrahydrocyanocyclopentane.

Starting with the tetracyanoethane (I) and the crotonaldehyde hydrazone (II), the title compound (V) is synthesized as shown in the reaction scheme.

Chemistry of 1,1,2,2-tetracyanoethane. Part 7. Synthesis and nucleophilic additions to one cyano group in 3-(N′,N′-dimethyl-n-acetylhydrazino)-5-methyl-1,1,2,2,-tetracyanocyclopentane

Conclusions1.Reactions of 1,1,2,2-tetracyanoethane were performed to give 3-(N′,N′-dimethyl-N-acetylhydrazino)-5-methyl-1,1,2,2-tetracyanocyclopentane. The latter reacted with nucleophiles to give 3-azabicyclo[3.3.0]oct-2-enes and 3-azabicyclo[3.3.0]oct-2-en-4-ones.2.X-ray analysis has been used to establish the stereochemistry of the cyclopentanes and bicyclic compounds derived from them.