Study on the synthesis of brassinolide and related compounds. Part 15. Formal synthesis of brassinolide via stereoselective sulphenate–sulphoxide transformation
Abstract
A formal synthesis of the natural growth-promoting steroid brassinolide is described, which involves construction of (22R,23E)-24-methyl-5β-cholest-23-ene-3α,6α,22-trio by methylation of (24R) and (24S)-(22E)-24-phenylsulphinyl-5β-cholest-22-ene-3α,6α-diol followed by 1,3-sulphoxidehydroxy transposition.