Ring Transformation of Glycidic Amides with Ortho-Metalated Phenols to Enantiopure 3-Hydroxychromanones
摘要:
A novel access to hitherto unknown enantiopure 2-alkylchroman-4-ones 10 was found by a reaction of ortho-metalated O-MOM-protected phenols with Weinreb amides 8 of enantiopure cis- or trans-glycidic acids, Upon acidic hydrolysis, the resulting o-MOMO-benzoyloxiranes 9 undergo ring transformation to 2-alkylchroman-4-ones 10. 2-Alkylidenecoumaran-3-ones 11 were formed as alternative products, depending on the configuration of the starting oxirane ring and on the type of phenol used as starting material.
Ring Transformation of Glycidic Amides with Ortho-Metalated Phenols to Enantiopure 3-Hydroxychromanones
摘要:
A novel access to hitherto unknown enantiopure 2-alkylchroman-4-ones 10 was found by a reaction of ortho-metalated O-MOM-protected phenols with Weinreb amides 8 of enantiopure cis- or trans-glycidic acids, Upon acidic hydrolysis, the resulting o-MOMO-benzoyloxiranes 9 undergo ring transformation to 2-alkylchroman-4-ones 10. 2-Alkylidenecoumaran-3-ones 11 were formed as alternative products, depending on the configuration of the starting oxirane ring and on the type of phenol used as starting material.
A novel access to hitherto unknown enantiopure 2-alkylchroman-4-ones 10 was found by a reaction of ortho-metalated O-MOM-protected phenols with Weinreb amides 8 of enantiopure cis- or trans-glycidic acids, Upon acidic hydrolysis, the resulting o-MOMO-benzoyloxiranes 9 undergo ring transformation to 2-alkylchroman-4-ones 10. 2-Alkylidenecoumaran-3-ones 11 were formed as alternative products, depending on the configuration of the starting oxirane ring and on the type of phenol used as starting material.