Total synthesis and properties of prostaglandins 30. Modification of (1S,5R)-2-oxabicyclo[3.3.0]-6-octen-3-one at the α-carbon atom

Derivatives of α-alkyl-, α-alkylidene-, and α-hydroxymethylene-2-oxabicyclo[3.3.0]-6-octen-3-one were obtained. The possibility of functional substitution of the bicyclic γ-lactones at the α position to the carbonyl group was thereby demonstrated.