Studies in asymmetric synthesis: Diastereoselective manipulation of chromatographically resolved pyranosides for the syntheses of natural products.

Persistent Link:
http://hdl.handle.net/10150/185232
Title:
Studies in asymmetric synthesis: Diastereoselective manipulation of chromatographically resolved pyranosides for the syntheses of natural products.
Author:
Arterburn, Jeffrey Burton.
Issue Date:
1990
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:
Chromatographic resolution of diastereomeric pyranosides prepared from enantiomerically pure α-hydroxy esters was shown to be a reliable method of obtaining a variety of potentially useful chiral substrates. Several enantiomerically pure α-hydroxy esters are commercially available and lead to chromatographically separable pyranosides. The methyl esters of lactic and mandelic acid are inexpensive, available in both enantiomeric forms, and were easily incorporated into readily available racemic pyran substrates. The resolutions were performed on a preparative scale using gravity driven silica gel column chromatography. Phenylselenyl substituted tetrahydropyranosides were prepared using the alkoxy-selenation reaction and were subjected to elimination under mild oxidative conditions to afford dihydropyranosides. The resolved chirality of the anomeric center permitted diastereoselective functionalization of the alkene moiety in these compounds. The dihydropyranosides possessing lactate or mandelate ester appendages preferentially underwent epoxidation with peroxy acids and cis-dihydroxylation with catalytic osmium tetroxide on the face of the alkene anti to the appendage. Reduction of the ester with lithium aluminum hydride converted the sterically demanding ester appendage into a polar primary alcohol. This enabled the appendage to participate in the delivery of electrophilic reagents such as peroxy acids and mercuric acetate preferentially to the syn-face of the dihydropyranoside alkene. Utilization of these general principles permitted the asymmetric syntheses of 4-deoxyribose, (R)-mevalonolactone, a protected mevinic acid precursor, and the calicheamicin ethylamino sugar.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Chemistry
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Chemistry; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Mash, Eugene A.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleStudies in asymmetric synthesis: Diastereoselective manipulation of chromatographically resolved pyranosides for the syntheses of natural products.en_US
dc.creatorArterburn, Jeffrey Burton.en_US
dc.contributor.authorArterburn, Jeffrey Burton.en_US
dc.date.issued1990en_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.abstractChromatographic resolution of diastereomeric pyranosides prepared from enantiomerically pure α-hydroxy esters was shown to be a reliable method of obtaining a variety of potentially useful chiral substrates. Several enantiomerically pure α-hydroxy esters are commercially available and lead to chromatographically separable pyranosides. The methyl esters of lactic and mandelic acid are inexpensive, available in both enantiomeric forms, and were easily incorporated into readily available racemic pyran substrates. The resolutions were performed on a preparative scale using gravity driven silica gel column chromatography. Phenylselenyl substituted tetrahydropyranosides were prepared using the alkoxy-selenation reaction and were subjected to elimination under mild oxidative conditions to afford dihydropyranosides. The resolved chirality of the anomeric center permitted diastereoselective functionalization of the alkene moiety in these compounds. The dihydropyranosides possessing lactate or mandelate ester appendages preferentially underwent epoxidation with peroxy acids and cis-dihydroxylation with catalytic osmium tetroxide on the face of the alkene anti to the appendage. Reduction of the ester with lithium aluminum hydride converted the sterically demanding ester appendage into a polar primary alcohol. This enabled the appendage to participate in the delivery of electrophilic reagents such as peroxy acids and mercuric acetate preferentially to the syn-face of the dihydropyranoside alkene. Utilization of these general principles permitted the asymmetric syntheses of 4-deoxyribose, (R)-mevalonolactone, a protected mevinic acid precursor, and the calicheamicin ethylamino sugar.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectChemistryen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorMash, Eugene A.en_US
dc.contributor.committeememberSteelink, Corneliusen_US
dc.contributor.committeememberBates, Robert B.en_US
dc.contributor.committeememberWigley, David E.en_US
dc.contributor.committeememberRemers, William A.en_US
dc.identifier.proquest9111921en_US
dc.identifier.oclc710153982en_US
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