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Asymmetric induction in 8? electrocyclizations. Design of a removable chiral auxiliary.

ABSTRACT: The pseudo C(2) symmetric trans diphenyl oxazoline group acts as an effective chiral auxiliary in the 8?, 6? tandem electrocyclization of a substituted tetraene 1-carboxylic acid. Assignment of absolute stereochemistry to the [4.2.0] bicyclooctadiene product supports a model in which both s-cis and s-trans conformations favor the transition states with the same helical twist. This assignment prefaces the development of analogs of SNF4435 C and D. These natural products demonstrate activity as androgen receptor antagonists and as multidrug resistance (mdr) reversal agents.

SUBMITTER: Kim K

PROVIDER: S-EPMC3320032 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature

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Asymmetric induction in 8π electrocyclizations. Design of a removable chiral auxiliary.

Kim Keunsoo K Lauher Joseph W JW Parker Kathlyn A KA

Organic letters 20111206 1

The pseudo C(2) symmetric trans diphenyl oxazoline group acts as an effective chiral auxiliary in the 8π, 6π tandem electrocyclization of a substituted tetraene 1-carboxylic acid. Assignment of absolute stereochemistry to the [4.2.0] bicyclooctadiene product supports a model in which both s-cis and s-trans conformations favor the transition states with the same helical twist. This assignment prefaces the development of analogs of SNF4435 C and D. These natural products demonstrate activity as an ...[more]

PMID: 22146007

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