The synthesis of a fused bicyclic thioglycoside analog of mycothiol, (3R)-3-acetylamino-4-one-6,7-dihydro-(1',2'-dideoxy-b-D-glucopyranoso)[2',1'-f]-1,5-thiazepane, is reported. Treatment of phthalimido-protected peracetylated glucosamine with N-acetyl-cysteine and boron trifluoride-etherate gave the b-linked thioglycoside, which was deprotected and cyclized, using HOBt and EDCl to form the lactam and giving the target structure. This mycothiol mimic and its tri-O-acetate will be investigated as potential inhibitors of enzymes involved in the biosynthesis of mycothiol. The protected deriv. also has the potential to be an a-selective N-cysteinyl glucosamine donor; however, initial glycosylation attempts failed due to the apparent stability of the fused bicyclic system. [on SciFinder (R)]