An efficient chemoenzymatic route to methyl 4-O-benzyl-2,3-anhydro-beta-D-lyxopyranoside from methyl beta-D-xylopyranoside.

Methyl 4-O-benzyl-2,3-anhydro-beta-D-lyxopyranoside, an intermediate for the preparation of methyl beta-D-xylopyranoside derivatives modified at C-2, was obtained in five steps in 58% yield. The synthetic sequence starts from methyl beta-D-xylopyranoside through two main steps involving regioselective enzymatic acetylation and deacetylation catalyzed by lipase PS.