Stereoselective functionalisation of SuperQuat enamides: asymmetric synthesis of homochiral 1,2-diols and alpha-benzyloxy carbonyl compounds
Homochiral (E)- and (Z)-enamides derived from SuperQuat (S)-4-phenyl-5,5-dimethyl-oxazolidin-2-one undergo highly diastereoselective epoxidation upon treatment with dimethyldioxirane. Subsequent epoxide opening with meta-chlorobenzoic acid proceeds via a stereoselective SN1-type process, with retent...
| Main Authors: | , , , , , , , , , , , , , , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
2008
|
| _version_ | 1826306257609293824 |
|---|---|
| author | Aciro, C Davies, S Garner, A Ishii, Y Key, M Ling, K Prasad, R Roberts, P Rodriguez-Solla, H O'Leary-Steele, C Russell, A Sanganee, H Savory, E Smith, A Thomson, J |
| author_facet | Aciro, C Davies, S Garner, A Ishii, Y Key, M Ling, K Prasad, R Roberts, P Rodriguez-Solla, H O'Leary-Steele, C Russell, A Sanganee, H Savory, E Smith, A Thomson, J |
| author_sort | Aciro, C |
| collection | OXFORD |
| description | Homochiral (E)- and (Z)-enamides derived from SuperQuat (S)-4-phenyl-5,5-dimethyl-oxazolidin-2-one undergo highly diastereoselective epoxidation upon treatment with dimethyldioxirane. Subsequent epoxide opening with meta-chlorobenzoic acid proceeds via a stereoselective SN1-type process, with retention of configuration, to give the corresponding 1′-m-chlorobenzoyl-2′-hydroxy derivatives. Treatment of the SuperQuat enamides with mCPBA effects this two-step transformation in one pot. Reductive cleavage of the isolated 1′-m-chlorobenzoyl-2′-hydroxy derivatives (≥96% de) generates homochiral 1,2-diols in ≥96% ee. Alternatively, regioselective lithiation of the enamide at C(1′) with tBuLi followed by reaction with an aromatic aldehyde and in situ O-benzylation generates a 1′-(benzyloxy-aryl-methyl) substituted enamide with high diastereoselectivity. Subsequent oxidative cleavage of the enamide C{double bond, long}C bond with NaIO4/RuCl3 followed by methanolysis of the resultant N-acyl fragment furnishes an O-benzyl protected α-hydroxy methyl ester in high ee. © 2008 Elsevier Ltd. All rights reserved. |
| first_indexed | 2024-03-07T06:45:12Z |
| format | Journal article |
| id | oxford-uuid:faa223f4-ea5f-4270-bad7-f6440f9b5ab9 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T06:45:12Z |
| publishDate | 2008 |
| record_format | dspace |
| spelling | oxford-uuid:faa223f4-ea5f-4270-bad7-f6440f9b5ab92022-03-27T13:07:32ZStereoselective functionalisation of SuperQuat enamides: asymmetric synthesis of homochiral 1,2-diols and alpha-benzyloxy carbonyl compoundsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:faa223f4-ea5f-4270-bad7-f6440f9b5ab9EnglishSymplectic Elements at Oxford2008Aciro, CDavies, SGarner, AIshii, YKey, MLing, KPrasad, RRoberts, PRodriguez-Solla, HO'Leary-Steele, CRussell, ASanganee, HSavory, ESmith, AThomson, JHomochiral (E)- and (Z)-enamides derived from SuperQuat (S)-4-phenyl-5,5-dimethyl-oxazolidin-2-one undergo highly diastereoselective epoxidation upon treatment with dimethyldioxirane. Subsequent epoxide opening with meta-chlorobenzoic acid proceeds via a stereoselective SN1-type process, with retention of configuration, to give the corresponding 1′-m-chlorobenzoyl-2′-hydroxy derivatives. Treatment of the SuperQuat enamides with mCPBA effects this two-step transformation in one pot. Reductive cleavage of the isolated 1′-m-chlorobenzoyl-2′-hydroxy derivatives (≥96% de) generates homochiral 1,2-diols in ≥96% ee. Alternatively, regioselective lithiation of the enamide at C(1′) with tBuLi followed by reaction with an aromatic aldehyde and in situ O-benzylation generates a 1′-(benzyloxy-aryl-methyl) substituted enamide with high diastereoselectivity. Subsequent oxidative cleavage of the enamide C{double bond, long}C bond with NaIO4/RuCl3 followed by methanolysis of the resultant N-acyl fragment furnishes an O-benzyl protected α-hydroxy methyl ester in high ee. © 2008 Elsevier Ltd. All rights reserved. |
| spellingShingle | Aciro, C Davies, S Garner, A Ishii, Y Key, M Ling, K Prasad, R Roberts, P Rodriguez-Solla, H O'Leary-Steele, C Russell, A Sanganee, H Savory, E Smith, A Thomson, J Stereoselective functionalisation of SuperQuat enamides: asymmetric synthesis of homochiral 1,2-diols and alpha-benzyloxy carbonyl compounds |
| title | Stereoselective functionalisation of SuperQuat enamides: asymmetric synthesis of homochiral 1,2-diols and alpha-benzyloxy carbonyl compounds |
| title_full | Stereoselective functionalisation of SuperQuat enamides: asymmetric synthesis of homochiral 1,2-diols and alpha-benzyloxy carbonyl compounds |
| title_fullStr | Stereoselective functionalisation of SuperQuat enamides: asymmetric synthesis of homochiral 1,2-diols and alpha-benzyloxy carbonyl compounds |
| title_full_unstemmed | Stereoselective functionalisation of SuperQuat enamides: asymmetric synthesis of homochiral 1,2-diols and alpha-benzyloxy carbonyl compounds |
| title_short | Stereoselective functionalisation of SuperQuat enamides: asymmetric synthesis of homochiral 1,2-diols and alpha-benzyloxy carbonyl compounds |
| title_sort | stereoselective functionalisation of superquat enamides asymmetric synthesis of homochiral 1 2 diols and alpha benzyloxy carbonyl compounds |
| work_keys_str_mv | AT aciroc stereoselectivefunctionalisationofsuperquatenamidesasymmetricsynthesisofhomochiral12diolsandalphabenzyloxycarbonylcompounds AT daviess stereoselectivefunctionalisationofsuperquatenamidesasymmetricsynthesisofhomochiral12diolsandalphabenzyloxycarbonylcompounds AT garnera stereoselectivefunctionalisationofsuperquatenamidesasymmetricsynthesisofhomochiral12diolsandalphabenzyloxycarbonylcompounds AT ishiiy stereoselectivefunctionalisationofsuperquatenamidesasymmetricsynthesisofhomochiral12diolsandalphabenzyloxycarbonylcompounds AT keym stereoselectivefunctionalisationofsuperquatenamidesasymmetricsynthesisofhomochiral12diolsandalphabenzyloxycarbonylcompounds AT lingk stereoselectivefunctionalisationofsuperquatenamidesasymmetricsynthesisofhomochiral12diolsandalphabenzyloxycarbonylcompounds AT prasadr stereoselectivefunctionalisationofsuperquatenamidesasymmetricsynthesisofhomochiral12diolsandalphabenzyloxycarbonylcompounds AT robertsp stereoselectivefunctionalisationofsuperquatenamidesasymmetricsynthesisofhomochiral12diolsandalphabenzyloxycarbonylcompounds AT rodriguezsollah stereoselectivefunctionalisationofsuperquatenamidesasymmetricsynthesisofhomochiral12diolsandalphabenzyloxycarbonylcompounds AT olearysteelec stereoselectivefunctionalisationofsuperquatenamidesasymmetricsynthesisofhomochiral12diolsandalphabenzyloxycarbonylcompounds AT russella stereoselectivefunctionalisationofsuperquatenamidesasymmetricsynthesisofhomochiral12diolsandalphabenzyloxycarbonylcompounds AT sanganeeh stereoselectivefunctionalisationofsuperquatenamidesasymmetricsynthesisofhomochiral12diolsandalphabenzyloxycarbonylcompounds AT savorye stereoselectivefunctionalisationofsuperquatenamidesasymmetricsynthesisofhomochiral12diolsandalphabenzyloxycarbonylcompounds AT smitha stereoselectivefunctionalisationofsuperquatenamidesasymmetricsynthesisofhomochiral12diolsandalphabenzyloxycarbonylcompounds AT thomsonj stereoselectivefunctionalisationofsuperquatenamidesasymmetricsynthesisofhomochiral12diolsandalphabenzyloxycarbonylcompounds |