The present invention relates to a process for preparing a lactone. The
process comprises the steps of reacting an aldehyde with an organic
halide in a carbon chain extension reaction to form an alcohol compound
comprising a functional group capable of allowing for carbonylation of
said alcohol compound, and then reacting said alcohol compound in a
carbonylation reaction to form an hydroxycarboxylic acid; and cyclizing
the hydroxycarboxylic acid to produce the lactone.