Syn-selective michael addition of amines to bis-enones: synthesis of 1,3,4,7-tetrasubstituted (4R,5S,6S,7R)-hexahydro-5,6-dihydroxy-2H-1,3-diazepin-2-ones

摘要

O-Protected 1,3,4,7-tetrasubstituted (4R,5S,6S,7R)-hexahydro-5,6-dihydroxy-2H-1,3-diazepin-2-ones 7a-d are seven-membered cyclic ureas useful as intermediates in the synthesis of HIV -proteinase ihibitors. We succeeded in preparing them using a three-step sequence starting from diethyl isopropylidene-L-tartrate 1. In a one-poit reaction 1 was transformed via an in situ generated aldehyde and subsequent Wittig reaction into the bis-enones 2a,b.