ChemInform Abstract: Enantioselective Synthesis of (3R,4E)-19-Methylicos-4-en-1-yn-3-ol, a Bioactive Metabolite of the Marine Sponge Cribrochalina vasculum

The first stereoselective synthesis of (3 R ,4 E )-19-methylicos-4-en-1-yn-3-ol, an immunosuppressive and antitumoral metabolite isolated from the Caribbean sponge Cribrochalina vasculum , has been achieved and its stereostructure has been confirmed. The key step of the synthesis involves a borane-mediated reduction of the parent ( E )-19-methyl-1-trimethylsilylicos-4-en-1-yn-3-one in the presence of a chiral oxazaborolidine.