Amino acid based diastereoselective synthesis of fucosamines
摘要:
Enantiomerically pure (+)-D-fucosamine 1, (+)-N-methyl-D-fucosamine 2 and (+)-3-O-methyl-D-fucosamine 3 (elsaminose) have been synthesised from known building blocks derived from natural amino acids. Direct and diastereoselective construction of the key intermediate 8 was accomplished by a highly syn,anti-selective aldol reaction between lithiated Schollkopf's bis-lactim ether 7 and the 1,3-dioxolane-4-carboxaldehyde 5. Elaboration of the common intermediate required optional methylation, selective hydrolysis of the bis-lactim ether in the presence of an isopropylidene ketal, lactonization and partial reduction of the carboxylic group. (C) 2002 Elsevier Science Ltd. All rights reserved.
Asymmetric Synthesis of D-Fucosamine and <i>N</i>-Methyl-D-Fucosamine
作者:Vicente Ojea、María Ruiz、José Quintela
DOI:10.1055/s-1997-696
日期:——
(+)-D-fucosamine and (+)-N-methyl-D-fucosamine (the amino sugar moiety of neocarzinostatin) have been synthesized from known building blocks derived from natural amino acids. Direct and diastereoselective construction of the key intermediate 4 was accomplished by a syn-aldol type reaction between Schöllkopf's bislactim ether 2 and the 1,3-dioxolane-4-carboxaldehyde 3. Reduction and monomethylation of a O'Donnell's Schiff base derived from the common amino ester 7 allows an optional access to the N-methyl derivative.
Amino acid based diastereoselective synthesis of elsaminose
作者:María Ruiz、Vicente Ojea、JoséMa Quintela
DOI:10.1016/0040-4039(96)01173-2
日期:1996.8
Optically pure (+)-elsaminose (2), the amino sugar contained in the antitumour antibiotic elsamicin A, has been synthesized in eight steps (26% overall yield) from known building blocks derived from glycine, L-valine, and L-threonine. Direct and selective construction of the key intermediate 6, with the complete backbone and the proper stereochemical configuration, is accomplished by a syn-aldol type
Amino acid based diastereoselective synthesis of fucosamines
作者:Marı́a Ruiz、Vicente Ojea、José M. Quintela
DOI:10.1016/s0957-4166(02)00376-2
日期:2002.8
Enantiomerically pure (+)-D-fucosamine 1, (+)-N-methyl-D-fucosamine 2 and (+)-3-O-methyl-D-fucosamine 3 (elsaminose) have been synthesised from known building blocks derived from natural amino acids. Direct and diastereoselective construction of the key intermediate 8 was accomplished by a highly syn,anti-selective aldol reaction between lithiated Schollkopf's bis-lactim ether 7 and the 1,3-dioxolane-4-carboxaldehyde 5. Elaboration of the common intermediate required optional methylation, selective hydrolysis of the bis-lactim ether in the presence of an isopropylidene ketal, lactonization and partial reduction of the carboxylic group. (C) 2002 Elsevier Science Ltd. All rights reserved.