SOME OBSERVATIONS ON THE STRUCTURE AND CONFORMATION OF ECHINOCYSTIC ACID, MACHAERINIC ACID, PROCERIC ACID, ACACIC ACID AND SAPOGENIN B (CORIACEOLIDE B)

Abstract

The paper deals with the structure and conformation of echniocystic acid, machaerinic acid, proceric acid, acacic acid and sapogenin B (Coriaceolide B). Modifications in the configuration of D/E ring junction from eis to trans have been suggested in case of proceric acid, acacic acid and sapogenin B (Coriaceolide B).

In the acetylation process acacic acid and proceric acid lactonise between 21–hydroxyl and 28–carboxyl groups simultaneously with acetylation of the other hydroxyl groups. On the basis of the evidences discussed the D and E ring junction in these acids is taken to be trans and consequentyl 18 α–H is suggested for sapogenin B (Coriaceolide B), proceric acid and acacic acid.

Echinocystic acid obtained from different sources gives different chemical reactions and are suggested to be isomers at the 18H (a and ß).