Hydroxylated α-vinylpyrrolidines from sugar-derived 2,5-dihydrofurans. Synthesis of (1S,2S,8aR)-1,2-dihydroxyindolizidine by ring closing olefin methathesis

Article abstract of DOI:10.1055/s-1997-1361

Sugar derived dihydrofurans carrying an amino function at the terminus of a two carbon branch undergo Hg(II)-promoted cyclization to give mercury substituted oxa-aza bicyclic compounds. Thiol promoted deoxymercuration results in cleavage of the tetrahyd rofuran ring and formation of hydroxylated 2-vinylpyrrolidines. These appear to be convenient precursors for the synthesis of indolizidines via ring-closing olefin metathesis. As an example the synthesis of a new lentiginosine epimer is reported.