The structure of capuramycin (1) is confirmed by an efficient synthesis that features glycosylation with a D-manno-pyranuronate donor 15 at the hindered C-5' hydroxyl of L-talo-uridine 10.
Ammonium salts from polymer-bound N-hydroxysuccinimide as solid-supported reagents for EDC-mediated amidations
作者:Rafael Chinchilla、David J Dodsworth、Carmen Nájera、José M Soriano
DOI:10.1016/s0040-4039(02)02592-3
日期:2003.1
New ammonium and alkylammonium salts derived from a polymeric N-hydroxysuccinimide (P-HOSu) have been prepared and used for the amidation of carboxylic acids and amino acids mediated by 1-ethyl-3-(3'-dimethylamino-propyl)carbodiimide hydrochloride (EDC). These polymer-supported ammonium salts afforded the corresponding amides in good yield, without detectable alpha-racemization and with easy recovery of the P-HOSu after the amidation reaction, being especially suitable for the amidation of Fmoc-protected amino acids. (C) 2002 Published by Elsevier Science Ltd.