Alkoxycarbonylation and selective deprotection of N-silyl derivatives of L-arginine
摘要:
N-delta,N-omega,O-Tris(trialkylsilyl)-N-alpha-carbobenzyloxy-L-arginine can be prepared in situ tom N-alpha-carbobenzyloxy-L-arginine. Treatment with alkyl chloroformates gives N-delta,N-omega-bis(alkyloxycarbonyl)-N-alpha-carbobenzyloxy-L-arginines, which can be converted into N-delta,N-omega-bis(alkyloxycarbonyl)-L-arginines by hydrogenation. (C) 1998 Elsevier Science Ltd. All rights reserved.
A facile, one-pot synthesis of N-alpha-t-Butyloxycarbonyl,N-delta,N-omegaBAR-di-benzyloxycarbonyl-L-Arginine (3a) and N-alpha,N-delta,N-omegaBAR-tri-benzyloxycarbonyl-L-Arginine (3b) is reported. N-alpha-t-Butyloxycarbonyl-L-Arginine (1b) is treated with trimethylsilylchloride and the tri-silylated intermediate 2c is subsequently allowed to react with benzyloxycarbonyl chloroformate to give 3a in 50% overall yield. Starting from 1a or 1c, 3b was prepared according to the same procedure in 72% and 60-85% yield, respectively.