A Simple Synthesis of Steroidal 3α,5-Cyclo-6-ones and their Efficient Transformation to Steroidal 2-En-6-ones

Article abstract of DOI:10.1055/s-1987-27882

Sterols 1 were converted to 3α-5-cyclo-6-ones 4 via their mesylates and subsequent oxidation.Refluxing 4 with sodium bromide/p-toluene sulfonic acid in dimethylformamide gave steroidal 2-en-6-ones 5, among which 5 is an important brassinolide intermediate.