학술논문
Effective Conversion of Three Diacetyl-C-(β-D-Glycopyranosyl) Phloroglucinols to Spiroketal Derivatives by Refluxing in Water.
Document Type
Article
Source
Subject
*CHEMISTRY
*CARBOHYDRATES
*HETEROCYCLIC compounds
*CHEMICAL structure
*ISOMERISM
*STEREOCHEMISTRY
*
*
*
*
*
Language
ISSN
0732-8303
Abstract
Refluxing of diacetylphloroglucinol C-β-D-gluco-, -galacto-, and -allopyranosides in water for 1 d gave two kinds of spiroketal derivatives in total yields of 77%, 74%, and 64%, respectively. The structure and stereochemistry of the six new spiro(benzofuran-[2H]pyran and -[2H]furan) derived from galactoside and alloside were verified by NMR analysis. The production ratios of the spiro derivatives were measured by HPLC analysis at regular time intervals. Since the majority of spiro(benzofuran-[2H]furan) were produced after 8 to 12 h of refluxing and most spiro(benzofuran-[2H]pyran) produced after 2 d of refluxing, it is assumed that formation of spirofuran and spiropyran is a kinetic- and thermodynamic-controlled reaction, respectively. [ABSTRACT FROM AUTHOR]