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Total synthesis of pyrano[3,2-e]indole alkaloid fontanesine B by a double cyclization strategy.

ABSTRACT: The regioselective synthesis of pyrano[3,2-e]indole alkaloid fontanesine B by two different cyclizations is described. The complete regioselectivity is controlled by the C4 Pictet-Spengler cyclization, in which an iminium ion acts as a transient directing (TDG) group. Furthermore, carbolines were constructed by a new Bischler-Napieralski-type cyclization, in which an unprecedented trichloromethyl carbamate serves as a reactive group.

SUBMITTER: Itoh T

PROVIDER: S-EPMC9062488 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature

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Total synthesis of pyrano[3,2-<i>e</i>]indole alkaloid fontanesine B by a double cyclization strategy.

Itoh Tomoki T Chiba Yuusuke Y Kawaguchi Shunsuke S Koitaya Yuki Y Yoneta Yuuma Y Yamada Koji K Abe Takumi T

RSC advances 20190301 18

The regioselective synthesis of pyrano[3,2-<i>e</i>]indole alkaloid fontanesine B by two different cyclizations is described. The complete regioselectivity is controlled by the C4 Pictet-Spengler cyclization, in which an iminium ion acts as a transient directing (TDG) group. Furthermore, carbolines were constructed by a new Bischler-Napieralski-type cyclization, in which an unprecedented trichloromethyl carbamate serves as a reactive group. ...[more]

PMID: 35520921

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