SYNTHESIS OF SOME DERIVATIVES OF PSEUDO-α-GALACTOPYRANOSE

Article abstract of DOI:10.1016/0008-6215(87)80164-7

Isopropylidenation of DL-(1,2/3,4,5)-5-hydroxymethyl-1,2,3,4-cyclohexanetetrol (1) with 2,2-dimethoxypropane in N,N-dimethylformamide in the presence of toluene-p-sulfonic acid gave the 1,2:3,4-, 1,2:4,7-, and 2,3:4,7-di-O-isopropylidene derivatives.Several C-7 substituted derivatives of 1 of biological interest have been prepared by nucleophilic displacement reactions of the tosylate derived from the most readily avaible 1,2:3,4-di-O-isopropylidene derivative 3.Condensation of 3 with 2,3,4,6-tera-O-acetyl-α-D-glucopyranosyl bromide gave diastereoisomeric products, which were converted into 7-O-(β-D-glucopyranosyl)-pseudo-α-D- (26A) and -L-galactopyranose (26B), the structures of which were confirmed by degradation of the octa-acetate of 26A, yielding the know pseudo-α-D-galactopyranose penta-acetate.