Role of a Protected Vicinal Diol Controller in Intramolecular [3 + 2] Cycloaddition Reactions of Chiral Acyclic Alkenyl Nitrones: Syntheses of Enantiomerically Pure Tetrasubstituted Cyclobutylamines
摘要:
Intramolecular cycloaddition reactions of C-5-chain acyclic alkenyl nitrones such as N-[(2S,3S)-2,3-bis-(tert-butyldimethylsiloxy)-4-pentenylidene]benzylamine N-oxide and its C(5)-substituted derivatives lead to fused isoxazolidines (bicyclo[3.2.0] framework) with very high diastereomeric excess. These isoxazolidines can readily be converted to optically active tetrasubstituted cyclobutylamines.
Role of a Protected Vicinal Diol Controller in Intramolecular [3 + 2] Cycloaddition Reactions of Chiral Acyclic Alkenyl Nitrones: Syntheses of Enantiomerically Pure Tetrasubstituted Cyclobutylamines
摘要:
Intramolecular cycloaddition reactions of C-5-chain acyclic alkenyl nitrones such as N-[(2S,3S)-2,3-bis-(tert-butyldimethylsiloxy)-4-pentenylidene]benzylamine N-oxide and its C(5)-substituted derivatives lead to fused isoxazolidines (bicyclo[3.2.0] framework) with very high diastereomeric excess. These isoxazolidines can readily be converted to optically active tetrasubstituted cyclobutylamines.