Strategies for the construction of morphinan alkaloid AB-rings: regioselective Friedel-Crafts-type cyclisations of gamma-aryl-beta-benzoylamido acids with asymmetrically substituted gamma-aryl rings
The regioselectivity of the Friedel-Crafts-type cyclisation of a range of γ-aryl-β-benzoylamido acids, bearing oxy substituents at the C(3)- and C(4)-positions of the γ-aryl ring, has been investigated. In all of the cases examined (with 3,4-dimethoxy, 3,4-methylenedioxy and 3-hydroxy-4-methoxy subs...
| Main Authors: | , , , , , , |
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| Format: | Journal article |
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Elsevier
2016
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| _version_ | 1797058785661943808 |
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| author | Davies, S Goddard, E Roberts, P Russell, A Smith, A Thomson, J Withey, J |
| author_facet | Davies, S Goddard, E Roberts, P Russell, A Smith, A Thomson, J Withey, J |
| author_sort | Davies, S |
| collection | OXFORD |
| description | The regioselectivity of the Friedel-Crafts-type cyclisation of a range of γ-aryl-β-benzoylamido acids, bearing oxy substituents at the C(3)- and C(4)-positions of the γ-aryl ring, has been investigated. In all of the cases examined (with 3,4-dimethoxy, 3,4-methylenedioxy and 3-hydroxy-4-methoxy substituents) the Lewis acid promoted cyclisation proceeds with exclusive regioselectivity for attack at the C(6)-position rather than at the C(2)-position, and furnishes the corresponding N- and O-protected 3-amino-6,7-dihydroxy-1-tetralone derivatives. This inherent regioselectivity can be overturned by the regioselective introduction of chlorine as a blocking group for the C(6)-position; subsequent Lewis acid promoted cyclisation then proceeds with exclusive regioselectivity for attack at the C(2)-position to deliver the corresponding N- and O-protected 3-amino-5-chloro-7,8-dihydroxy-1-tetralone derivative. These complementary cyclisation protocols represent useful methods for the preparation of these benzo-fused carbocyclic ring systems, which are the functionalised AB-rings of a range of morphinan alkaloids. |
| first_indexed | 2024-03-06T19:55:15Z |
| format | Journal article |
| id | oxford-uuid:2557fbf5-ebb6-4c58-b9c9-d8132912ba16 |
| institution | University of Oxford |
| last_indexed | 2024-03-06T19:55:15Z |
| publishDate | 2016 |
| publisher | Elsevier |
| record_format | dspace |
| spelling | oxford-uuid:2557fbf5-ebb6-4c58-b9c9-d8132912ba162022-03-26T11:55:13ZStrategies for the construction of morphinan alkaloid AB-rings: regioselective Friedel-Crafts-type cyclisations of gamma-aryl-beta-benzoylamido acids with asymmetrically substituted gamma-aryl ringsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:2557fbf5-ebb6-4c58-b9c9-d8132912ba16Symplectic Elements at OxfordElsevier2016Davies, SGoddard, ERoberts, PRussell, ASmith, AThomson, JWithey, JThe regioselectivity of the Friedel-Crafts-type cyclisation of a range of γ-aryl-β-benzoylamido acids, bearing oxy substituents at the C(3)- and C(4)-positions of the γ-aryl ring, has been investigated. In all of the cases examined (with 3,4-dimethoxy, 3,4-methylenedioxy and 3-hydroxy-4-methoxy substituents) the Lewis acid promoted cyclisation proceeds with exclusive regioselectivity for attack at the C(6)-position rather than at the C(2)-position, and furnishes the corresponding N- and O-protected 3-amino-6,7-dihydroxy-1-tetralone derivatives. This inherent regioselectivity can be overturned by the regioselective introduction of chlorine as a blocking group for the C(6)-position; subsequent Lewis acid promoted cyclisation then proceeds with exclusive regioselectivity for attack at the C(2)-position to deliver the corresponding N- and O-protected 3-amino-5-chloro-7,8-dihydroxy-1-tetralone derivative. These complementary cyclisation protocols represent useful methods for the preparation of these benzo-fused carbocyclic ring systems, which are the functionalised AB-rings of a range of morphinan alkaloids. |
| spellingShingle | Davies, S Goddard, E Roberts, P Russell, A Smith, A Thomson, J Withey, J Strategies for the construction of morphinan alkaloid AB-rings: regioselective Friedel-Crafts-type cyclisations of gamma-aryl-beta-benzoylamido acids with asymmetrically substituted gamma-aryl rings |
| title | Strategies for the construction of morphinan alkaloid AB-rings: regioselective Friedel-Crafts-type cyclisations of gamma-aryl-beta-benzoylamido acids with asymmetrically substituted gamma-aryl rings |
| title_full | Strategies for the construction of morphinan alkaloid AB-rings: regioselective Friedel-Crafts-type cyclisations of gamma-aryl-beta-benzoylamido acids with asymmetrically substituted gamma-aryl rings |
| title_fullStr | Strategies for the construction of morphinan alkaloid AB-rings: regioselective Friedel-Crafts-type cyclisations of gamma-aryl-beta-benzoylamido acids with asymmetrically substituted gamma-aryl rings |
| title_full_unstemmed | Strategies for the construction of morphinan alkaloid AB-rings: regioselective Friedel-Crafts-type cyclisations of gamma-aryl-beta-benzoylamido acids with asymmetrically substituted gamma-aryl rings |
| title_short | Strategies for the construction of morphinan alkaloid AB-rings: regioselective Friedel-Crafts-type cyclisations of gamma-aryl-beta-benzoylamido acids with asymmetrically substituted gamma-aryl rings |
| title_sort | strategies for the construction of morphinan alkaloid ab rings regioselective friedel crafts type cyclisations of gamma aryl beta benzoylamido acids with asymmetrically substituted gamma aryl rings |
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