Abstract: Provided are methods of carbonylating cyclic substrates to produce carbonylated cyclic products. The cyclic substrates may be 2, 2-di substituted epoxides and the cyclic products may be ?,?-di substituted lactones. The method may be carried out by forming and pressurizing a reaction mixture of the cyclic substrate, a solvent, carbon monoxide, and a [LA+][CO(CO)4?] catalyst, where [LA+] is a Lewis acid capable of coordinating to the cyclic substrate. The method may proceed with a regio selectivity of 90:10 or greater. The resulting carbonylated cyclic products may be converted to ketone aldol products that retain the stereochemistry and enantiomeric ratio of the carbonylated cyclic products.