2-Keto sugars as preformed heterocyclic building blocks. Synthetic studies

The synthesis of a series of bicyclic 2-hexulose derivatives (5), (6) and (7), which provide access to regiospecific carbohydrate-based ketone enolates, is described. The preparation of silyl enol ethers (21) and (22) from keto ether (5) and keto acetal (6), respectively, is also reported