Wohl Degradation; Zemplén Modification

A. Wohl, Ber. 26, 730 (1893); 32, 3666 (1899); G. Zemplén, Ber. 59, 1254, 2402 (1926).

Method for the conversion of an aldose into an aldose with one less carbon atom by the reversal of the cyanohydrin synthesis. In the Wohl method the nitrile group is eliminated by treatment with ammoniacal silver oxide; in the Zemplén modification sodium alkoxide is used in the elimination of the nitrile:

Reviews: V. Deulofeu, Advan. Carbohyd. Chem. 4, 129, 138 (1949); R. Bognár et al., Ann. 680, 118 (1964); W. W. Wendall, Tetrahedron Letters 1970, 3439; L. Hough, A. C. Richardson, The Carbohydrates 1A, 128 (1972).