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Condensation of 1,6-N,O-carbonyl-3-N-ethoxycarbonyl-2,5-dideoxystreptamine (7) with 6-azido-2,3,4-tri-O-benzyl-6-deoxy-α-D-glucopyranosyl chloride by the Koenigs–Knorr reaction produced the α-glycoside 10. The cyclic carbamate of 10 was opened with ethanol in the presence of sodium ethoxide and the resulting 4-O-(6-azido-2,3,4-tri-O-benzyl-6-deoxy-α-D-glucopyranosyl)-N,N′-diethoxycarbonyl-2,5-dideoxystreptamiue (12) was glycosidated with 3-acetamido-2,4,6-tri-O-benzyl-3-deoxy-α-D-glucopyranosyl chloride (21) to give the α,α-diglycoside 22. Hydrogenation of the azido group and removal of the protective groups gave 5-deoxykanamycin A (25), an antibiotic with a potency about half that of kanamycin A.

The preparation of (4-tritylthio-2-azetidinon-l-yl)triphenylphosphoranylideneacetates from 4-acetoxyazetidin-2-one is described. They are easily converted to mercuric or silver mercaptides. These mercaptides are acylated with a wide variety of acylating agents and cyclized to 2-substituted penem-3-carboxylates.