Studies of cholesterol biosynthesis. 1. A new chemical degradation of cholesterol

Abstract

A new method for the degradation of the ring structure of cholesterol is descr. This involves the opening of ring B by oxidation and the splitting off of ring A as 2_methylcyclohexanone by pyrolysis. C atom 8 is obtained as CO2 from the decarboxylation of 5,6_secocholestan-5,7-dion-6-oic acid. From the further degradation of 2-methylcyclohexanone, C 4 and C 5 of cholesterol are obtained as acetic acid and C atoms 19, 10, 1, 2 and 3 as valeric acid; by a side reaction C 19, 10, and 5 were isolated as propionic acid accompanied by C 4, 3, 2, and 1 as butyric acid. 2 different ways are descr. for carrying out the early stages of the degradation: the 1st method starts from cholesterol ozonide, the 2nd and more efficient method from cholest-5-ene.