A Novel Enantioselective Synthesis of (+)-Biotin

Article abstract of DOI:10.1016/S0040-4039(00)79354-3

A conceptually simple enantioselective 14-step synthesis of (+)-biotin from L-cysteine is reported based upon an intramolecular 1,3-dipolar cyclodaddition sequence involving (i) elimination of bromide 8 to the endocyclic thioenol ether 9, (ii) thermolysis of the ene carbamoyl azide 9 to the exocyclic thioenol ether 10.Both the synthesis of 8 and the final transformation of 10 into (+)-biotin are based upon literature precedents.