An efficient stereoselective synthesis of [3S(1S,9S)]-3-[[[9-(benzoylamino) octahydro-6,10-dioxo-6H-pyridazino-(1,2-a)(1,2)-diazepin-1-yl]-carbonyl ]amino]-4-oxobutanoic acid, an interleukin converting enzyme (ICE) inhibitor.

The title compound 1 is a potent interleukin-1β-converting enzyme (ICE) inhibitor. Recently, an efficient chiral synthesis of compound 1 has been accomplished in our labs. The overall yield of this 18-step stereoselective synthesis was 9.8%.