Patent ID: 7250522

Claim:
A method for preparing an aryl 5-thio-β-D-aldohexopyranoside derivative of Formula (III), which comprises reacting a 5-thio-D-aldohexopyranose derivative of Formula (I) with Ar-OH of Formula (II) in the presence of a phosphine represented by PR 11 R 12 R 13 and an azo reagent represented by R 21 —N═N—R 22 in accordance with the following scheme: wherein in the above Formulae (I) and (III), the wavy lines mean containing any stereoisomer selected from D-form, L-form and a mixture thereof, Y represents —O— or —NH—, and R 1 , R 2 , R 3 and R 4 , which may be the same or different, each represent a hydrogen atom, a C 2-10 acyl group, a C 1-6 alkyl group, a C 7-10 aralkyl group, a C 1-6 alkoxy-C 7-10 aralkyl group, an allyl group, a tri(C 1-6 alkyl)silyl group, a C 1-6 alkoxy-C 1-6 alkyl group or a C 2-6 alkoxycarbonyl group, or when Y represents —O—, R 1 and R 2 , R 2 and R 3 , or R 3 and R 4 may together form —C(R A )(R B )— wherein R A and R B , which may be the same or different, each represent a hydrogen atom, a C 1-6 alkyl group or a phenyl group, in the above Formula (II), Ar represents an aryl group which may be substituted with any substituent, in PR 11 R 12 R 13 , R 11 to R 13 , which may be the same or different, each represent a phenyl group which may be substituted with a C 1-6 alkyl group, a pyridyl group or a C 1-6 alkyl group, and in R 21 —N═N—R 22 , R 21 and R 22 , which may be the same or different, each represent a C 2-5 alkoxycarbonyl group, an N,N-di-C 1-4 alkylaminocarbonyl group or a piperidinocarbonyl group.