反应详情

The preparation of compound 9 is outlined in Scheme 1. Commercially available tert-butyl (R)-3-hydroxypyrrolidine-1-carboxylate (compound 1) is treated with methanesulfonyl chloride to give tert-butyl (R)-3-(methylsulfonyloxy)pyrrolidine-1-carboxylate (compound 2), which then is reacted with diethylmalonate and a suitable base (e.g., potassium tert-butoxide or sodium ethoxide) to give diethyl (R)-2-(1-(tert-butoxycarbonyl)pyrrolidin-3-yl)malonate (compound 3) with inverted stereochemistry around the chiral carbon.