反应详情

Due to its low cost, L aspartic acid appears to be the most attractive starting material for the preparation of (S)-3-amino-1-substituted-pyrrolidines. The literature method from L-aspartate (D. T. Witiak, loc. cit.) involves treatment of N-boc-L-aspartate with acetic anhydride to give (S)-3-(tert butoxycarbonylamino)succinic anhydride followed by addition of a primary amine and ring closure with heat to give the succinimide, (S)-3-(tert-butoxycarbonylamino)-1-substituted pyrrolidine-2,5-dione. The latter is then reduced and deblocked to give the 1-substituted-3-aminopyrrolidine in low overall yield. From our experience with this method some racemization takes place when the blocking group is p-toluenesulfonyl(tosyl) and the primary amine is benzylamine.