Studies of Aminosugars. XXII. The Total Synthesis of Kanamycin A

Abstract 6-O-(3-Amino-3-deoxy-α-d-glucopyranosyl)-2-deoxystreptamine, which was previously synthesized, was masked with carbobenzoxy, isopropylidene and benzyl groups to give 6-O-(2-O-benzyl-3-carbobenzoxyamino-3-deoxy-4,6-O-isopropylidene-α-d-glucopyranosyl)-N,N′-dicarbobenzoxy-2-deoxystreptamine, with which 2,3,4-tri-O-benzyl-6-(N-benzylacetamido)-6-deoxy-α-d-glucopyranosyl chloride was condensed by a modified Koenigs-Knorr reaction, to give an α,α-diglycoside compound. The identity of the product with a substance of the same structure derived from natural kanamycin A was shown. Removal of the masking groups gave the synthetic kanamycin A, which was identical to the natural specimen.