Role of the A1,3 allylic interaction on the stereochemistry of formation of Schiff's bases derived from bicyclo[2.2.1]hept-5-en-2-one and 7-oxabicyclo[2.2.1]hept-5-en-2-one

Abstract

The stereochemistry of formation of Schiff's bases derived from norbornen-2-one and 7-oxanorbornen-2-one has been studied by ¹H and ¹³C n.m.r. spectroscopy. Elucidation of the reason for the preference for the E-isomer in both cases has been attempted by molecular mechanics calculations. This preference may be justified by A^1.3 allylic interactions.