摘要：

Specific and effective procedures are described for the conversion of a variety of substituted 1,3-dithianes to carbonyl compounds by means of mercury(II)-promoted hydrolysis or oxidative cleavage by N-bromo- or N-chlorosuccinimide. The conditions required for the mercury(II)-promoted hydrolysis of 1,3-dithianes may be correlated with the ease of C-S heterolysis and the electron-supplying ability of the substituents at C(2). The hydrolysis by the mercury method of 2,2-dialkyl derivatives is generally very facile and more rapid than that of 2-monoalkyl-1,3-dithianes, while the hydrolysis of 2-acyl-1,3-dithianes is very slow. For the latter cases especially the use of the N-halosuccinimides is advantageous, and three reagents of this type have been devised for use in aqueous acetonitrile or acetone: (1) N-bromosuccinimide alone, (2) N-bromosuccinimide with silver ion, and (3) N-chlorosuccinimide with silver ion. The use of the N-chlorosuccinimide-silver ion reagent is advantageous for unsaturated dithianes, since olefinic linkages are unaffected by it. 2,6-Lutidine and 2,4,6-collidine may be employed to buffer the three reagents in applications to acid-sensitive substrates. A number of aldehydes and ketones have been obtained in 70-100% yields using the halosuccinimide reagents.

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