Mg-Al 3 : 1 hydrotalcite catalyst in the synthesis of cyclopropane carboxylic acid derivatives

The non-activated Mg-Al 3:1 hydrotalcite is a suitable basic catalyst both in the intramolecular cyclization reaction of malonic acid allylic esters i nto bicyclic cyclopropane carboxylic acid lactones and the intermolecular c yclization reaction of dibromoethane and diethyl malonate into cyclopropane dicarboxylic acid diester. The optimal reaction conditions of the intramol ecular cyclization were determined using a 2(4) factorial design. An intere sting effect on the diastereoselectivity of the intramolecular cyclization was observed compared with the diastereoselectivity of this cyclization usi ng solid potassium carbonate as base. (C) 2000 Elsevier Science B.V. All ri ghts reserved.