An efficient cis-reduction of alkyne to alkene in the presence of a vinyl iodide: stereoselective synthesis of the C22-C31 fragment of leiodolide A

Rapid and efficient reduction of alkyne bond in the presence of a vinyl iodide is established using freshly prepared Brown's P2-Ni as the catalyst, affording the semihydrogenated alkene products in good to excellent yields (73-91%). Based on this new method, a stereoselective synthesis of the key C22-C31 fragment of marine macrolide leiodolide A has been developed.