Diastereoselective cyclopropanations of alpha,beta-unsaturated ketals derived from chiral hydrobenzoin

Persistent Link:
http://hdl.handle.net/10150/276784
Title:
Diastereoselective cyclopropanations of alpha,beta-unsaturated ketals derived from chiral hydrobenzoin
Author:
Torok, Daniel Seth, 1963-
Issue Date:
1988
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
2-Cycloalken-1-one-(-)-erythro-hydrobenzoin ketals undergo efficient and diastereoselective cyclopropanation when treated with an excess of Simmons-Smith reagent. The resulting crystalline products yield enantiomerically pure cyclopropyl compounds upon recrystallization. For example, 2-cyclohexen-1-one-(-)-erythro-hydrobenzoin ketal gave, in 90% yield, a 19:1 mixture of diastereomeric cyclopropanes as established by 62.9 MHz ¹³C NMR spectroscopy. Upon one recrystallization, diastereomerically pure cyclopropane was obtained in 78% recovery. Hydrolysis gave (+)-norcaranone of greater than 99% ee. Three other examples are presented which demonstrate the advantages of hydrobenzoin ketals over previously used homochiral ketals, as well as several techniques for the synthesis of chiral hydrobenzoin.
Type:
text; Thesis-Reproduction (electronic)
Keywords:
Ketones.; Benzoin.
Degree Name:
M.S.
Degree Level:
masters
Degree Program:
Graduate College; Chemistry
Degree Grantor:
University of Arizona
Advisor:
Mash, Gene A.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleDiastereoselective cyclopropanations of alpha,beta-unsaturated ketals derived from chiral hydrobenzoinen_US
dc.creatorTorok, Daniel Seth, 1963-en_US
dc.contributor.authorTorok, Daniel Seth, 1963-en_US
dc.date.issued1988en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstract2-Cycloalken-1-one-(-)-erythro-hydrobenzoin ketals undergo efficient and diastereoselective cyclopropanation when treated with an excess of Simmons-Smith reagent. The resulting crystalline products yield enantiomerically pure cyclopropyl compounds upon recrystallization. For example, 2-cyclohexen-1-one-(-)-erythro-hydrobenzoin ketal gave, in 90% yield, a 19:1 mixture of diastereomeric cyclopropanes as established by 62.9 MHz ¹³C NMR spectroscopy. Upon one recrystallization, diastereomerically pure cyclopropane was obtained in 78% recovery. Hydrolysis gave (+)-norcaranone of greater than 99% ee. Three other examples are presented which demonstrate the advantages of hydrobenzoin ketals over previously used homochiral ketals, as well as several techniques for the synthesis of chiral hydrobenzoin.en_US
dc.typetexten_US
dc.typeThesis-Reproduction (electronic)en_US
dc.subjectKetones.en_US
dc.subjectBenzoin.en_US
thesis.degree.nameM.S.en_US
thesis.degree.levelmastersen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorMash, Gene A.en_US
dc.identifier.proquest1334312en_US
dc.identifier.oclc22755014en_US
dc.identifier.bibrecord.b17495684en_US
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