Enzymatic β-glycosidation of primary alcohols

For the purpose of finding the best reaction conditions of β-glucosidation of primary alcohols, screening experiments in respect of the enzymes, glycosyl donors and solvents were carried out. The effective enzyme and glycosyl donor for the synthesis of benzyl β-d-glucopyranoside (4) appeared to be β-glucosidase (EC 3.2.1.21) from almonds and 4-nitrophenyl β-d-glucopyranoside (7), respectively. Enzymatic glycosidation of 10 kinds of primary alcohols (methanol, ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, 2-methoxyethanol, 2-ethoxyethanol, benzyl alcohol, (S)-(−)-perillyl alcohol) gave stereoselectively the corresponding β-d-glucopyranosides (14–21, 4 and 22) in moderate yield, respectively.