Hydrogenation of alkyl 2-oximino-or-D-arnbino-hexopyranosides in the presence of palladium on charcoal and hydrochloric acid gave mixtures of the alkyl 2-amino-2-deoxy-or-D-hexopyranoside hydrochlorides with the gluco and tnniii~o configurations in about 90% yields. The fraction of gl~tco compound varied substantially with the nature of the alkyl group; viz., methyl, 71 %; ethyl or 11-propyl, 62%; isopropyl, 80 %. More of the Inatvzo compound is formed, viz., isopropyl, 50 %, when the 3,4,6-triacetate of the oximinoglycoside is hydrogenated. Hydrogenation of methyl 6-0-(2-oximino-a-Dnrabit~o-hexopyranosy1)-8-D-glucopyranoside gave an about equimolar mixture of the two configurations.Canadian Journal of Chemistry, 46, 397 (1968) The occurrence of 2-amino-2-deoxy-a-glycopyranosyl groups in a wide variety of antibiotics (1) has rendered the synthesis of such glycosides (a-glycosaininides) a leading problem in carbohydrate chemistry. p-Glycosaminides in which the aglycon is either the residue of a simple alcohol or a more complex carbohydrate structure can normally be obtained via the KoenigsKnorr reaction or its modifications (2). The yield depends strongly on the complexity of the potential aglycon. To date there exists no controlled synthesis of complex a-glycosaminides in appreciable yield. Of the various methods employed, alcoholysis of the parent sugar or derivative in the presence of acid proceeds in best yield (3). However this method is inherently limited to simple acid-resistant alcohols. For more coinplex alcohols, for example appropriately blocked carbohydrate structures, only low yields of a-glycosaminides are available usually via Koenigs-Knorr type reactions (4). The reduction of the 2-oximino-a-hexopyranosides, which are formed in high yield on reaction of alcol~ols with the nitrosyl chloride adduct of acetylated glycals (5, 6), offered a new approach to these compounds and is the subject of this paper. The work is concerned mainly with the preparation of alkyl glycopyranosaminides from simple alkyl (methyl, ethyl, iz-propyl, and isopropyl) alcohols which are normally best prepared by alcoholysis of the aminosugars. Nevertheless, the data provide an insight to the factors which affect the stereochemical routes of the reductions. Also, the result obtained in the pre-'Presented at the Symposium on Synthesis, Organic Division, Chemical Institute of Canada, Banff, Alberta, August 31 -September 2, 1966.paration of a mixture of methyl 6-0-(2-amino-2-deoxy-a-D-glucopyran0syl)-p-D-glucopyranoside with the corresponding a-D-manno isomer is described as an illustration of an a-linked disaccharide synthesis.The alkyl 2-amino-2-deoxy-a-D-glucopyranosides formed in the reductions were identified by direct comparisons with authentic samples prepared from D-glucosamine and this comprises proof of the a-D-configuration for the parent oxinzino-glycosides.' The formation of alkyl 2 -amino -2-deoxy -a -D -mannopyranosides was based on this fact together with nuclear magnetic resonance (n.m.r.) data for these compoun...