Abstract Partial hydrolysis of per-O-acetyl-and per-O-benzoyl derivatives of 1, 6-anhydro-β-D- glucopyranose with methanolic hydrogen chloride and hydrazine hydrate was investigated. The acyl group at C (3) is of substantial influence on the course of hydrolysis. The esterified hydroxyl group at C (3) was found to be most stable on acid hydrolysis with methanolic hydrogen chloride when compared with that at C (2), or C (4); on the other hand, this ester ...