UNIQUE TEMPLATE EFFECTS OF DISTANNOXANE CATALYSTS IN TRANSESTERIFICATION OF DIOL ESTERS

1,n-Diol diacetates (n = 2,3,4) are selectively converted into the cor responding monoacetates by distannoxane-catalyzed transesterification. Such unique selectivity is not encountered with 1,n-diol diacetates w here n greater-than-or-equal-to 5. A great difference in reactivity is also seen in the transesterifiaction between methyl butyrate and l,n- diol monoacetates: the ethylene glycol derivative sluggishly undergoes transesterification whereas higher homologs react smoothly. The uniqu e template effects of the catalysts are discussed in terms of cooperat ion of two different tin atoms which are located in the proximity.