Chemoenzymatic synthesis of (+)-docosa-4,15-dien-1-yn-3-ol, a component of the marine sponge Cribrochalina vasculum, and confirmation of the structure and absolute configuration of the acetylenic alcohol, by lipase-catalysed biotransformations

Abstract

The (4E,15Z)- and (4E,15E)-isomers of (+)-docosa-4,15-dien-1-yn-3-ol 1, isolated from the marine sponge Cribrochalina vasculum, were synthesized in highly enantiomerically pure form by lipase-mediated biotransformation with Novozym 435, and the structure of 1 from the natural product was proved to be (4E,15Z)-docosa-4,15-dien-1-yn-3-ol 1Z. The absolute configuration of C-3 in compound (+)-1Z was assigned as S on the basis of the conversion of (+)-1Z into (R)-(–)-docosan-3-ol 17, which was also prepared from oct-7-en-3-ol 12 via biotransformation with lipase Novozym.