Ojima lactam

The Ojima lactam is an organic compound of some importance in the commercial production of Taxol.

The reaction centers around an imine - lithium enolate cycloaddition.

In order to ensure the correct stereochemistry (the phenyl group and the silyl ether must adopt a cis configuration) in the β-lactam a chiral auxiliary is used in the enolate synthesis.

The benzyl group is then removed and replaced by a TES silyl ether by reaction with triethylsilyl chloride.

Both imine and enole intermediate join in a cycloaddition reaction followed by an intramolecular substitution of the amine with expulsion of the chiral auxiliary to the cis-lactam.