Reduction of the Gulono-l,4-lactones and Derivatives

A variety of methods has been developed for the reduction of the gulonolactones and derivatives to D- and L-gulose and the corresponding derivatives. D-Gulono-1,4-lactone (2) was reduced to D-gulose (d- 

9) with sodium amalgam in 50-60% yield.133,134 The same reduction was accomplished in —75% yield135,136 with sodium borohydride at pH 3-4 (to prevent the formation of sodium D-gulonate). By using pyridine -oxolane as the solvent, lithium aluminum hydride was successfully used in the preparation of D-gulose (59%) from D-gulono-1,4-lactone,137 even in the presence of an excess of the hydride. 

Nucleophilic Additions to the Carbonyl Group of Derivatives of the Gulono-1,4-lactones 

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