Synthesis of Nonano-9-lactone Fused to a δ-Lactone Ring

Abstract

With the goal of obtaining fused dilactones, the carbohydrate moiety of diastereoisomeric Michael adducts of levoglucosenone and cyclohexanone was converted to δ-lactone and its derivatives fused to an octahydrochromene fragment. The subsequent oxidative cleavage of the C-C bridge in the latter by the action of pyridiniun chlorochromate (PCC) afforded nonano-9-lactone fused at the C⁶-C⁷ bond to δ-lactone or methyl-δ-lactol. The presence of a carbonyl group in the carbohydrate moiety was found to prevent C-C bond cleavage.