Confirmation of the structure of a glucono-1,4-lactone derivative obtained from silylation of glucono-1,5-lactone

Silylation reactions of glucono-1,5-lactone can give the persilylated glucono-1,5-lactone or the persilylated 1,4-lactone depending on the reaction conditions employed. The structure of 2,3,5,6-tetra-O-(tert-butyldimethylsilyl)-d-glucono-1,4-lactone, obtained in 84% yield from the reaction of glucono-1,5-lactone with TBSOTf and lutidine in dichloromethane, has been confirmed by X-ray crystallography. Formation of the glucono-1,5-lactone and manno-1,5-lactone derivatives and other possible products has also been ruled out by synthesis of possible exo-glycal derivatives of these lactones using the Ramberg–Bäcklund rearrangement of the corresponding sulfones.