An approach to the bicyclic core of the zaragozic acids via the aldol reaction between methyl (α-D-xylofuranoside)uronate and D-(R)-glyceraldehyde acetonide
作者:Pierre Fraisse、Issam Hanna、Jean-Yves Lallemand、Thierry Prangé、Louis Ricard
DOI:10.1016/s0040-4020(99)00637-7
日期:1999.10
The aldol reaction between methyl (methyl-3-O-benzyl-2-O-methoxymethyl-alpha-D-xylofurano-side)uronate and D-(R)-glyceraldehyde acetonide, promoted by cerium(III) chloride, led to three diastereoisomers in good yield and high level of stereoselectivity at the newly created quaternary center of the furanoside. Under acidic conditions, the aldol derivatives undergo transketalization to afford different bicyclic ketal isomers. This reaction was used as the key step in the synthesis of a functionalized bicyclic core of the zaragozic acids. (C) 1999 Elsevier Science Ltd. All rights reserved.