The cyclic ester (111) was readily hydrolyzed to the dibasic acid (IV). On being heated the latter lost carbon dioxide, giving a deeply colored oil from which three acidic substances were isolated-small amounts of the stereoisomeric monobasic acids (V) and the lactone (VI). 11. was of major interest to see if these cyclic substances would react like the other cyclopropane derivatives having one unsubstituted carbon atom'when treated with ...