Diastereoselective Silylene/Ireland-Claisen Rearrangement

Significance

The reaction adresses the challenge of creating quaternary centers with good stereocontrol. Using the highly reactive silylene reagent 5, simple α,β-unsaturated esters like 4 undergo concomitant silylene transfer and Ireland-Claisen rearrangement to lead to highly functionalized chiral silalactones 6. An application of this domino reaction was demonstrated by the total synthesis of 5-epi-acetomycin (9). The silalactone 6 was converted into the desired (+)-9 in eight steps.