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Synthesis of (-)-Hebelophyllene?E: An Entry to Geminal Dimethyl-Cyclobutanes by [2+2] Cycloaddition of Alkenes and Allenoates.

ABSTRACT: The first synthesis of hebelophyllene?E is presented, along with assignment of its previously unknown relative configuration through synthesis of epi-ent-hebelophyllene?E. Development of a catalytic enantioselective [2+2] cycloaddition of alkenes and allenoates provides access to the required chiral geminal dimethylcyclobutanes. Key to its success is the identification of a novel oxazaborolidine catalyst which promotes the cycloaddition in high enantioselectivities with good functional-group tolerance (9 examples, up to 97:3 e.r.). Thus, a late-stage cycloaddition using a fully functionalized alkene, followed by a diastereoselective reduction allows a concise entry to this class of natural products.

SUBMITTER: Wiest JM

PROVIDER: S-EPMC5939599 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature

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Synthesis of (-)-Hebelophyllene E: An Entry to Geminal Dimethyl-Cyclobutanes by [2+2] Cycloaddition of Alkenes and Allenoates.

Wiest Johannes M JM Conner Michael L ML Brown M Kevin MK

Angewandte Chemie (International ed. in English) 20180324 17

The first synthesis of hebelophyllene E is presented, along with assignment of its previously unknown relative configuration through synthesis of epi-ent-hebelophyllene E. Development of a catalytic enantioselective [2+2] cycloaddition of alkenes and allenoates provides access to the required chiral geminal dimethylcyclobutanes. Key to its success is the identification of a novel oxazaborolidine catalyst which promotes the cycloaddition in high enantioselectivities with good functional-group tol ...[more]

PMID: 29481716

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