263023-22-9Relevant academic research and scientific papers
Enantioselective synthesis of unsaturated amino acids using p- methoxybenzylamine as an ammonia equivalent
Alcon, Montserrat,Moyano, Albert,Pericas, Miquel A.,Riera, Antoni
, p. 4639 - 4651 (2007/10/03)
A versatile, non-alkylative enantioselective synthesis of unsaturated α-amino acids based on the Sharpless asymmetric epoxidation has been developed. Enantiomerically enriched trans epoxy alcohols bearing unsaturated substituents were prepared and submitted to regio- and stereospecific ring- opening with p-methoxybenzylamine as a nucleophile, leading to anti-3-(p- methoxybenzylamino)-1,2-diols which were further protected by reaction with Boc2O. The 1,2-diol fragment was then oxidatively cleaved by a sequential treatment with sodium periodate and sodium chlorite to afford the corresponding amino acid. Using this methodology, doubly N-protected (p- methoxybenzyl and Boc) allyl glycine, 3-butenyl glycine and 4-pentenyl glycine have been prepared in three synthetic steps from the corresponding allyl alcohols. As a demonstration of the orthogonal nature of the nitrogen protection, both protecting groups have been selectively removed from the fully protected amino ester. (C) 1999 Elsevier Science Ltd.
