Alkoxycarbonylation and selective deprotection of N-silyl derivatives of L-arginine

N(δ),N(ω),O-Tris(trialkylsilyl)-N(α)-carbobenzyloxy-L-arginine can be prepared in situ from N(α)-carbobenzyloxy-L-arginine. Treatment with alkyl chloroformates gives N(δ),N(ω)-bis(alkyloxycarbonyl)-N(α)-carbobenzyloxy- L-arginines, which can be converted into N(δ),N(ω)-bis(alkyloxycarbonyl)- L-arginines by hydrogenation.