PREPARATION OF 2-ZINCIO-1,3-DITHIANES AND DI(1,3-DITHIAN-2-YL)ZINC AND THEIR REACTION WITH HIGHLY FUNCTIONALIZED HALIDES AND ALPHA,BETA-UNSATURATED CARBONYL-COMPOUNDS

The title compounds were obtained by simple transmetallation of the co rresponding lithium derivatives with ZnCl2, or ZnBr2. Contrary to 2-li thio-1,3-dithianes, 2-zincio-1,3-dithianes can react with a number of electrophiles bearing reactive functional groups to afford highly subs tituted I,3-dithianes in satisfactory to excellent yields. The synthes is of the new organozinc derivative, di(1,3-dithian-2-yl)zinc, which e fficiently adds to enones, is also reported.