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Article: Substituent effects on regioselective intramolecular oxidation of unactivated C-H bonds: Stereoselective synthesis of substituted tetrahydropyrans

TitleSubstituent effects on regioselective intramolecular oxidation of unactivated C-H bonds: Stereoselective synthesis of substituted tetrahydropyrans
Authors
Issue Date2003
PublisherAmerican Chemical Society. The Journal's web site is located at http://pubs.acs.org/journals/jacsat/index.html
Citation
Journal Of The American Chemical Society, 2003, v. 125 n. 1, p. 158-162 How to Cite?
AbstractOur previously reported intramolecular δ-selective C-H bond oxidation by dioxiranes, generated in situ from activated ketones, offers a novel approach to the synthesis of tetrahydropyrans. To synthesize substituted tetrahydropyrans in a stereoselective manner, we examined the effects of alkyl, nitrogen, and oxygen substituents at the α-,β-, and γ-sites of ketones on the stereoselectivities of intramolecular C-H bond oxidation reactions. Ketones 1-4 with a methyl group at the α-, β-, or γ-site showed the diastereo-selectivities that agreed with the trans/cis ratio predicted by considering steric interactions in the transition states. Furthermore, ketones 5 and 6 carrying a bulky phthalimido group at the α- and the β-sites, respectively, exhibited excellent stereoselectivity, each affording only one diastereomer. However, ketones 9 and 10 bearing β-oxygen substituents gave reversed stereoselectivity as compared to those with β-alkyl or nitrogen substituents, possibly because of the hydrogen bonding interaction in the transition state. For ketones 12 and 13, both bearing methyl and silyloxy groups, the hydrogen bonding interaction was probably more important than the steric effect on the diastereoselectivity of intramolecular oxidation of C-H bonds.
Persistent Identifierhttp://hdl.handle.net/10722/69508
ISSN
2023 Impact Factor: 14.4
2023 SCImago Journal Rankings: 5.489
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorWong, MKen_HK
dc.contributor.authorChung, NWen_HK
dc.contributor.authorHe, Len_HK
dc.contributor.authorYang, Den_HK
dc.date.accessioned2010-09-06T06:14:18Z-
dc.date.available2010-09-06T06:14:18Z-
dc.date.issued2003en_HK
dc.identifier.citationJournal Of The American Chemical Society, 2003, v. 125 n. 1, p. 158-162en_HK
dc.identifier.issn0002-7863en_HK
dc.identifier.urihttp://hdl.handle.net/10722/69508-
dc.description.abstractOur previously reported intramolecular δ-selective C-H bond oxidation by dioxiranes, generated in situ from activated ketones, offers a novel approach to the synthesis of tetrahydropyrans. To synthesize substituted tetrahydropyrans in a stereoselective manner, we examined the effects of alkyl, nitrogen, and oxygen substituents at the α-,β-, and γ-sites of ketones on the stereoselectivities of intramolecular C-H bond oxidation reactions. Ketones 1-4 with a methyl group at the α-, β-, or γ-site showed the diastereo-selectivities that agreed with the trans/cis ratio predicted by considering steric interactions in the transition states. Furthermore, ketones 5 and 6 carrying a bulky phthalimido group at the α- and the β-sites, respectively, exhibited excellent stereoselectivity, each affording only one diastereomer. However, ketones 9 and 10 bearing β-oxygen substituents gave reversed stereoselectivity as compared to those with β-alkyl or nitrogen substituents, possibly because of the hydrogen bonding interaction in the transition state. For ketones 12 and 13, both bearing methyl and silyloxy groups, the hydrogen bonding interaction was probably more important than the steric effect on the diastereoselectivity of intramolecular oxidation of C-H bonds.en_HK
dc.languageengen_HK
dc.publisherAmerican Chemical Society. The Journal's web site is located at http://pubs.acs.org/journals/jacsat/index.htmlen_HK
dc.relation.ispartofJournal of the American Chemical Societyen_HK
dc.titleSubstituent effects on regioselective intramolecular oxidation of unactivated C-H bonds: Stereoselective synthesis of substituted tetrahydropyransen_HK
dc.typeArticleen_HK
dc.identifier.openurlhttp://library.hku.hk:4550/resserv?sid=HKU:IR&issn=0002-7863&volume=125&spage=158&epage=162&date=2003&atitle=Substituent+Effects+on+Regioselective+Intramolecular+Oxidation+of+Unactivated+C-H+bonds:++Stereoselective+Synthesis+of+Substituted+Tetrahydropyransen_HK
dc.identifier.emailYang, D:yangdan@hku.hken_HK
dc.identifier.authorityYang, D=rp00825en_HK
dc.description.naturelink_to_subscribed_fulltext-
dc.identifier.doi10.1021/ja028357len_HK
dc.identifier.pmid12515517-
dc.identifier.scopuseid_2-s2.0-0037425509en_HK
dc.identifier.hkuros75916en_HK
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-0037425509&selection=ref&src=s&origin=recordpageen_HK
dc.identifier.volume125en_HK
dc.identifier.issue1en_HK
dc.identifier.spage158en_HK
dc.identifier.epage162en_HK
dc.identifier.isiWOS:000180227400033-
dc.publisher.placeUnited Statesen_HK
dc.identifier.scopusauthoridWong, MK=7403908449en_HK
dc.identifier.scopusauthoridChung, NW=8759035900en_HK
dc.identifier.scopusauthoridHe, L=55074306200en_HK
dc.identifier.scopusauthoridYang, D=7404800756en_HK
dc.identifier.issnl0002-7863-

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