Lipases in the Regioselective Preparation of Glyceric Acid Esters of Methyl Glycosides

: Sundell Riku, Kanerva Liisa T

Publisher: Wiley-VCH Verlag GmbH & Co. KGaA, Weinham

: 2013

: European Journal of Organic Chemistry

: EurJOC

: 22

: 4971

: 4978

: 8

: 1434-193X

DOI: https://doi.org/10.1002/ejoc.201300450

The lipase-catalyzed regioselective acylation of methyl α-Dgalacto-, -gluco- and -mannopyranosides with isopropylidene-protected (R)- and (S)-glyceric acid methyl esters in organic solvents is presented. Factors affecting the formation of the 6-O-mono- and 2,6-O-diacylated products are examined and preparative-scale reactions are detailed. In addition, studies on partially protected methyl α-D-galactopyr-anosides are presented, with the 3,4-O-isopropylidene protected compound leading exclusively to the formation of the
6-O-monoacylated product even at high substrate concentrations. Application of acidic resin in methanol allows removal of the isopropylidene protection groups without disturbing the ester bond at C-6.