Highly stereoselective ring opening reaction of tropone oxime tosylate with nucleophiles

Abstract

The tosylate (1) of tropone oxime undergoes a novel ring-opening reaction under mild conditions with secondary amines, alkoxides, and Grignard reagents affording stereoselectively 6-substituted (1Z,3Z,5Z)-hexa-1,3,5-triene-carbonitriles (2a–h) as sole products in high yields; these are easily converted into Z,Z,E-isomers (3a–h) with acids and further into E,E,E-isomers (4a–h) as the final form by stronger acid or by passing the solution over a column of alumina.