Biosynthesis of natural products. Part 2. Syntheses of 14C- or 3H-labelled ent-kaur-16-ene derivatives oxygenated at C-7, or at C-7 and C-15, from epicandicandiol

Abstract

ent-Kaur-16-en-7α-ol (12a), ent-kaur-16-en-7-one (14a), ent-kaur-16-en-7β-ol (15a), ent-15-oxokaur-16-en-7α-ol (22a), and ent-kaur-16-ene-7,15-dione (23a), and the labelled compounds (12b), (14b), (14c), (15b), (22b), (23b), and (23c), which are required for the investigation on the biosynthetic route from ent-kaur-16-ene (1) into enmein (3) and oridonin (4), were synthesised from epicandicandiol (5).