Document Detail


Direct kinetic formation of nonanomeric [6.5]-spiroketals in aqueous media.
MedLine Citation:
PMID:  18004871     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The direct kinetic formation of spiroketals from mixed ketal-alcohol precursors under acid catalysis was studied using four differently substituted systems. In all cases, the exclusive formation of the anomeric isomer was observed under equilibrating conditions. However, the formation of the nonanomeric spiroketal isomer was observed if the reaction was performed under kinetic conditions using an appropriately tuned acid. Water had a dramatic accelerating effect on the spiroketalization reactions that were performed in THF, and the highest yields of the nonanomeric products were obtained in aqueous THF. The nonanomeric/anomeric product ratio was also strongly affected by the substituents and the stereochemistry of the starting alcohol.
Authors:
Daniele Castagnolo; Irene Breuer; Petri M Pihko
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2007-11-16
Journal Detail:
Title:  The Journal of organic chemistry     Volume:  72     ISSN:  0022-3263     ISO Abbreviation:  J. Org. Chem.     Publication Date:  2007 Dec 
Date Detail:
Created Date:  2007-12-14     Completed Date:  2008-03-25     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  2985193R     Medline TA:  J Org Chem     Country:  United States    
Other Details:
Languages:  eng     Pagination:  10081-7     Citation Subset:  IM    
Affiliation:
Laboratory of Organic Chemistry, Helsinki University of Technology, P.O.B. 6100, FI-02015 TKK, Espool, Finland.
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MeSH Terms
Descriptor/Qualifier:
Alcohols / chemistry
Catalysis
Kinetics
Molecular Conformation
Spiro Compounds / chemical synthesis*,  chemistry
Stereoisomerism
Water / chemistry
Chemical
Reg. No./Substance:
0/Alcohols; 0/Spiro Compounds; 7732-18-5/Water

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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