Chemoenzymatic Synthesis of Sacranosides A and B

Direct beta-glucosidation between (-)-myrtenol and nerol and D-glucose (3) using the immobilized beta-glucosidase from almonds with the synthetic prepolymer ENTP-4000 gave myrtenyl O-beta-D-glucoside (4) and neryl O-beta-D-glucoside (10), respectively. The coupling of the myrtenyl or neryl O-beta-D-glucopyranoside congeners (7 or 13) and 2,3,4-tri-O-benzoyl-beta-L-arabinopyranosyl bromide (8) afforded the coupled products (9 or 14), respectively. Deprotection of the coupled products (9 or 14) afforded the synthetic myrtenyl 6-O-alpha-L-arabinopyranosyl-beta-D-glucopyranoside (Sacranoside A, 1) or neryl 6-O-alpha-L-arabinopyranosyl-beta-D-glucopyranoside (Sacranoside B, 2), respectively.