摘要:
                                Condensation of]-[4,6-di-O-(tert-butyldimethylsilyl)-2,3-dideoxy-alpha-D-erythro-hex-2-enopyranosyl]-4-bromobenzene (2) with methyl 2-acetamidoacrylate in the presence of Pd(OAc)(2), P(C6H4-O-CH3)(3), and AgNO3, afforded the unsaturated C-glycosyl enamido ester 3d in 80% yield. Reduction of compound 3d in the presence of [Rh(COD)(R,R)-(Et-DuPHOS)]OTf gave the corresponding unsaturated C-glycosyl (R)-phenylalanine derivative, when the [Rh(COD)(S,S)-(Et-DuPHOS)]OTf catalyst gave the C-glycosyl (S)-phenylalanine derivative, in 67 and 79% yield, respectively. Bis-hydroxylation of compound 4, followed by acetylation afforded the C-mannopyranosyl phenylalanine derivative 5 in overall 30% yield. (C) 2002 Elsevier Science Ltd. All rights reserved.