TOTAL SYNTHESIS OF (R)-DIHYDROACTINIDIOLIDE AND (R)-ACTINIDIOLIDE USING ASYMMETRIC CATALYTIC HETERO-DIELS-ALDER METHODOLOGY

The total synthesis of the naturally occurring bicyclic lactones (R)-d ihydroactinidiolide and (R)-actinidiolide is presented. The key step i n the syntheses is the copper(II)-bisoxazoline-catalyzed hetero-Diels- Alder reaction of a cyclic diene with ethyl glyoxylate giving the hete ro-Diels-Alder product in high yield and with very high regio-, diaste reo-, and enantioselectivity. The total syntheses proceed via an inter mediate, which also has the potential for a series of other natural pr oducts. The structure of the key intermediate is confirmed by X-ray an alysis.