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

✍ Scribed by A. B. Zolotoi; P. M. Lukin; S. V. Konovalikhin; M. Yu. Skvortsova; O. E. Nasakin; L. O. Atovmyan

• Publisher: Springer US
• Year: 1991
• Tongue: English
• Weight: 535 KB
• Volume: 27
• Category: Article
• ISSN: 0009-3122
• DOI: 10.1007/bf00480841

✦ Synopsis

The problems of the structure-.-property interrelationship of 3.imino-2-oxabicyclo[ 2.21]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 inzino group are analyzetL 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 C~3---Csez, C~j--C s_ and C =N exo bonds and the correlation of the XDS and IR spectroscopic data are examined. From ~e XDS data for N-bromo-substituted imines, a model for Br+..

.N=--C electrophilic attack was proposed

The synthesis, spectral and structural evidence for the structure, and a probable pathway for the formation of bicyclic imino esters I and II [2, 3] from 1,1,2,2-tetracyanoethane and s-cis-ct,~-unsaturated ketones [2, 3] have been previously reported. In the present research, on the basis of data from an x-ray diffraction analysis of I-IV and qualitative MO theory we established a pathway for the formation of the bicyclic imino esters, analyzed their structures, studied the stereochemistry of the bromination of imino ester I, and determined the structural aspect of the electrophilic addition of bromine to the CEN bond.t NC-" .~CN NC "~J"'~ R R~ ,...3~---Me 2 X/'" "-fl N-'.Ri I-.IV