The acetolysis of 4,4-diethylcholesteryl mesylate gave 11% 3,4-dialkyl (A), 39% 3α,5-cyclo (C), and 50% A-norcholestene (B) derivatives. The corresponding yield for the 4-4,dimethyl series is 25, < 11.6, and > 61.4%.
The stereochemistry of the title compound was determined.
The buffered hydrolysis of 4β-ethyl-4α-methylcholest-5-en-3β-yl mesylate and 4α-ethyl-4β-methylcholest-5-en-3β-yl mesylate has been studied. Both reactions resulted in a predominance of ring-contracted products accompanied by small, but significant, amounts of products derived from stereospecific alkyl shifts. A chair–boat equilibrium is postulated to explain these results.