Synthesis of Mono-and Dicarba-disaccharides

Synthesis of Carba-maltose, Carba-isomaltose, Carba-cellobiose, 

The carba-trehaloses are carbocyclic analogs of trehalose, in which one or both of the D-glucopyranose units is (are) replaced with D-carba-glucopy-ranose, and may be expected to act as a substrate analog or an inhibitor of 

Trehalosamine, 2-amino-2-deoxy-a-D-glucopyranosyl a-D-glucopy-ranoside (343), is an antibiotic produced by Streptomyces tavendulae. Four related compounds, the 3-amino-3-deoxy and 4-amino-4-deoxy isomers,  

3- amino-3-deoxy-a-D-glucopyranosyl 3-amino-3-deoxy-) -D-glucopyrano-side have been shown to possess antibacterial activity. 

Coupling of 237 with the protected 2-amino-2-deoxy-o -D-glucopyranosyl bromide (348) in dichloromethane in the presence of silver triflate afforded a diastereoisomeric mixture. The isomer related to the natural one was depro-tected with sodium in liquid ammonia, to give the carba-trehalosamine 

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