Liquid-phase parallel synthesis of 2-aryl-5-methoxylcarbonyl-dihydropyrones using soluble polymer support

General and efficient methods for the construction of 2-aryl-5-methoxylcarbonyl-dihydropyrones on soluble polymer support have been developed. The hetero-Diels–Alder reaction of aldehydes with poly(ethylene glycol) (PEG)-bound Danishefsky’s diene derived from PEG-bound acetoacetate, followed by cleavage from the support, afforded 2-aryl-5-methoxylcarbonyl-dihydropyrones. The products were obtained in good yields and high enantioselectivities.