Homolytic addition of esters of alkanedicarboxylic acids to alkyl maleates

Abstract

1. The reaction of alkyl maleates with the methyl and ethyl esters of glutaric, adipic, azelaic, and sebacic acids, initiated by tert-butyl peroxide, gives the 1∶1 and 2∶1 adducts. From the methyl esters of the investigated acids, using a 10-fold mole excess, the 1∶1 and 2∶1 adducts are formed in a ratio ranging from 0.9∶1 to 1.4∶1, while the ethyl esters they are formed in a ratio ranging from 1.9∶1 to 2.3∶1. The use of a 20-fold excess of the ester increases this ratio to ∿4∶1. 2. Two types of adducts are obtained from the esters of glutaric and adipic acids: the addition products of the alkyl maleate to the α-C atoms of the acyl and alkoxyl portions of the ester addend. The addition of the methyl esters of azelaic and sebacic acids to the alkyl maleate takes place predominantly (over 90%) at the carbon atom adjacent to the methoxycarbonyl group.