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Asymmetric synthesis of chromanone lactones via vinylogous conjugate addition of butenolide to 2-ester chromones.

ABSTRACT: Chiral chromanone lactones are a class of natural products with important biological activity. We report a direct diastereo- and enantioselective vinylogous conjugate addition of butenolide to 2-ester substituted chromones. The transformation proceeded well in the presence of as low as 1 mol% of a chiral N,N'-dioxide/Sc^III complex, 3 Å MS and a catalytic amount of hexafluoroisopropanol (HFIP). The scope of Michael acceptors includes a variety of substituted chromones at different positions, and the desired chromanone lactones upon reduction are afforded in good yield and diastereoselectivity, and excellent enantioselectivity (up to 99% ee). The strategy could be used in the concise synthesis of blennolide C and gonytolide A, C and G.

SUBMITTER: Li Y

PROVIDER: S-EPMC9350614 | biostudies-literature | 2022 Aug

REPOSITORIES: biostudies-literature

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Asymmetric synthesis of chromanone lactones via vinylogous conjugate addition of butenolide to 2-ester chromones.

Li Yi Y Xin Shuang S Weng Rui R Liu Xiaohua X Feng Xiaoming X

Chemical science 20220705 30

Chiral chromanone lactones are a class of natural products with important biological activity. We report a direct diastereo- and enantioselective vinylogous conjugate addition of butenolide to 2-ester substituted chromones. The transformation proceeded well in the presence of as low as 1 mol% of a chiral N,N'-dioxide/ScIII complex, 3 Å MS and a catalytic amount of hexafluoroisopropanol (HFIP). The scope of Michael acceptors includes a variety of substituted chromones at ...[more]

PMID: 35975160

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