An Alternative Route for Synthesis of Chiral 4-Substituted 1-Arenesulfonyl-2-imidazolidinones: Unusual Utility of (4S,5S)- and (4R,5R)-4,5-Dimethoxy-2-imidazolidinones and X-Ray Crystallography

Abstract

An unusual synthesis of (S)-1-arenesulfonyl-4-(1-adamantyl)-2-imidazolidinones15a–dand (R)-1-arenesulfonyl-4-tert-butyl-2-imidazolidinones19a–dhas been developed fromtrans-1-apocamphanecarbonyl-4,5-dimethoxy-2-imidazolidinones6and7as chiral synthons. Diastereomerically puretrans-1-apocamphanecarbonyl-4,5-dimethoxy-2-imidazolidinones6and7were successfully subjected to regioselective reduction using bulky organocuprates that afforded 1-apocamphanecarbonyl-5-methoxy-2-imidazolidinones10and11. This new finding was used for synthesis of chiral 4-substituted 2-imidazolidinones15a–dand19a–dthrough the corresponding intermediates13and17by treatment with steric bulkytert-butylcuprate or 1-adamantylcuprate.