Toward the synthesis of fine chemicals from lactose: preparation of d-xylo and l-lyxo-aldohexos-5-ulose derivatives
摘要:
The transformation of (5R)-2,6-di-O-benzyl-5-C-methoxy-beta-D-galactopyranosyl-(1 -> 4)-2,3:5,6-di-O-iso-propylidene-aldehydo-D-glucose dimethyl acetal (8) into partially protected derivatives of D-xylo- and L-lyxo-aldohexos-5-ulose has been reported, applying appropriate epimerisation methods to its 3'-O- and 4'-O-protected alcoholic derivatives. (C) 2009 Elsevier Ltd. All rights reserved.
The transformation of (5R)-2,6-di-O-benzyl-5-C-methoxy-beta-D-galactopyranosyl-(1 -> 4)-2,3:5,6-di-O-iso-propylidene-aldehydo-D-glucose dimethyl acetal (8) into partially protected derivatives of D-xylo- and L-lyxo-aldohexos-5-ulose has been reported, applying appropriate epimerisation methods to its 3'-O- and 4'-O-protected alcoholic derivatives. (C) 2009 Elsevier Ltd. All rights reserved.
Useful access to enantiomerically pure protected inositols from carbohydrates: the aldohexos-5-uloses route
by changing the reaction conditions, and two isomeric inositolderivatives were obtained with complete stereoselection from each inosose. The presented approach permits us to control the configuration of three out of the six stereocentres of the inositol frame and gives access to seven of the nine inositols. Noteworthy, for the D-xylo derivative, the two-step sequence (condensation followed by reduction