Synthesis of the intermediate of Biotin

(R)-tert-butyl (1-((tert-butyldimethylsilyl)thio)but-3-yn-2-yl) carbamate, an key intermediate of the natural product Biotin which is a water-soluble vitamin, involved in an essential part of the metabolic cyle causing catalytic fixation of carbon dioxide in the biosynthesis of fatty acids, sugars, and a-amino acids, was synthesized from L-cystine in overall yield 41% through five steps, including esterification, N-tert-butyl carbamoylation, TBS protection, reduction and Corey-Fuchs reaction.