Several anhydrides have been subjected to the trichloromethylation reaction using sodium trichloroacetate in dimethoxyethane solution. The trichloromethylation products exist in either of two tautomeric forms, the keto acid or the lactol. If the trichloroacetyl and carboxyl groups are held in fixed coplanarity, the stability of the lactol tautomer is quite high and the compound crystallizes in that form. If the groups are not held coplanar, then the keto acid ...
