Simple preparations of alkyl and cycloalkyl alpha-glycosides of maltose, cellobiose, and lactose.

Alkyl, cycloalkyl, allyl, 4-pentenyl, and benzyl alpha-glycosides of maltose, cellobiose, and lactose were prepared (17-77% yield; alpha/beta=70/30-96/4) via a direct reaction of the free disaccharides with a binary AcBr-AcOH mixture, followed by glycosidation with alcohol using FeCl3 in MeNO2 or CH2Cl2, Zemplén deacetylation, and resolution of the anomeric mixture of glycosides by chromatography. Using MeCN as solvent for the glycosidation step, the corresponding beta-biosides were also prepared (16-61% yield; alpha/beta=25/75-5/95).