A short stereoselective synthesis of (+)- and (−)-2-oxabicyclo[3.3.0]oct-6-en-3-one by intramolecular carbon–hydrogen insertion catalyzed by chiral dirhodium(II) carboxamidates

Abstract

The synthesis of (1 S,5 R)-(−)-2-oxabicyclo[3.3.0]oct-6-en-3-one, a useful synthetic precursor en route to various prostaglandins, from divinylcarbinol via catalytic metathesis and CH insertion of 3-cyclopentenyl diazoacetate is described. Enantioselectivities of 90±1% have been achieved in the insertion process.