Abstract
A metal-free, Brønsted acid, pTsOH-catalyzed intramolecular rearrangement of δ-hydroxyalkynones to substituted 2,3-dihydro-4 H-pyran-4-ones was developed. The rearrangement occurs with high regioselectivity under mild and open-air conditions. The scope of work was illustrated by synthesizing an array of aliphatic and aromatic substituted 2,3-dihydro-4 H-pyran-4-ones in up to 96% yield, 100% atom economy, and complete regioselectivity. Some of the dihydropyranones are utilized for vinylic halogenations and to complete the total synthesis of bioactive natural products, obolactone and a catechol pyran isolated from Plectranthus sylvestris ( Labiatae) .
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Alkynes / chemistry*
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Benzenesulfonates / chemistry*
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Biological Products / chemical synthesis*
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Biological Products / chemistry
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Biological Products / isolation & purification
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Catalysis
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Catechols / chemical synthesis*
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Catechols / chemistry
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Catechols / isolation & purification
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Lactones / chemical synthesis*
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Lactones / chemistry
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Lactones / isolation & purification
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Molecular Conformation
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Plectranthus / chemistry*
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Pyrans / chemical synthesis*
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Pyrans / chemistry
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Pyrans / isolation & purification
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Pyrones / chemical synthesis
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Pyrones / chemistry*
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Stereoisomerism
Substances
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Alkynes
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Benzenesulfonates
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Biological Products
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Catechols
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Lactones
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Pyrans
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Pyrones
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obolactone
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4-toluenesulfonic acid