... Tetrahedron. Volume 57, Issue 1, 1 January 2001, Pages 227–233. ... Under similar conditions 3β-methanosulfonate of 5α,6α-androstan-17-one (9d) and stigmasterol (9f) gave A ring aromatization products 4-methylestra-1,3,5(10)-triene-17-one (10b) and 4-methylstigmast-1,3, ...