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A diastereoselective formal synthesis of berkelic acid.

ABSTRACT: A formal synthesis of berkelic acid is reported. The strategy employs the combination of a chiral exocyclic enol ether and an achiral isochromanone to afford the chroman spiroketal core via a base-triggered generation and cycloaddition of an o-quinone methide intermediate. Other key steps include equilibration of the spiroketal, intramolecular benzylic oxidation, and lactone addition/hemiketal reduction; all occur with good diastereoselectivity.

SUBMITTER: Wenderski TA

PROVIDER: S-EPMC3107127 | biostudies-literature | 2011 Jan

REPOSITORIES: biostudies-literature

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A diastereoselective formal synthesis of berkelic acid.

Wenderski Todd A TA Marsini Maurice A MA Pettus Thomas R R TR

Organic letters 20101207 1

A formal synthesis of berkelic acid is reported. The strategy employs the combination of a chiral exocyclic enol ether and an achiral isochromanone to afford the chroman spiroketal core via a base-triggered generation and cycloaddition of an o-quinone methide intermediate. Other key steps include equilibration of the spiroketal, intramolecular benzylic oxidation, and lactone addition/hemiketal reduction; all occur with good diastereoselectivity. ...[more]

PMID: 21138313

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