Abstract
The regioselective opening of the F ring of 22-oxo-23-spiroketals using a saturated solution of HCl in acetic anhydride yielded novel cholestanic frameworks with pyranone or cyclopentenone E rings. The structures of the new derivatives of sarsasapogenin, diosgenin and hecogenin thus obtained were established using one and two dimensional (1)H, (13)C experiments (DEPT, COSY, HETCOR, HMBC, ROESY, and NOESY). The X-ray analysis for compound 11b confirmed the 23R configuration for the new stereogenic center.
Copyright © 2012 Elsevier Inc. All rights reserved.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Acetic Anhydrides / chemistry
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Cholestanes / chemistry*
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Crystallography, X-Ray
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Cyclopentanes / chemistry*
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Diosgenin / chemistry
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Furans / chemistry*
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Hydrochloric Acid / chemistry
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Magnetic Resonance Spectroscopy / methods
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Models, Chemical
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Molecular Structure
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Pyrones / chemistry*
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Sapogenins / chemistry
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Spiro Compounds / chemistry*
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Spirostans / chemistry
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Stereoisomerism
Substances
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Acetic Anhydrides
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Cholestanes
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Cyclopentanes
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Furans
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Pyrones
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Sapogenins
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Spiro Compounds
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Spirostans
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spiroketal
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acetic anhydride
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hecogenin
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sarsasapogenin
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Diosgenin
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cyclopentenone
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Hydrochloric Acid