摘要 |
A synthesis is described for intermediates which are readily amenable to the large scale preparation of hydroxyethylurea-based chiral HIV protease inhibitors. The method includes forming a diastereoselective epoxide compound of formula (I) from a chiral alpha amino aldehyde and halomethyllithium as an organometallic methylene-adding reagent. In formula (I) R<1> is selected from alkyl, aryl, cycloalkyl, cycloalkylalkyl and arylalkyl, which are optionally substituted with a group selected from alkyl, halogen, NO2, OR<9> or SR<9>, where R<9> represents hydrogen or alkyl; and P<1> and P<2> independently are selected from amine protecting groups, including but not limited to, arylalkyl, substituted arylalkyl, cycloalkenylalkyl and substituted cycloalkenylalkyl, allyl, substituted allyl, acyl, alkoxycarbonyl, aralkoxycarbonyl and silyl. |