Li Yi, Xin Shuang, Weng Rui, Liu Xiaohua, Feng Xiaoming
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University Chengdu 610064 China
Chem Sci. 2022 Jul 5;13(30):8871-8875. doi: 10.1039/d2sc02541h. eCollection 2022 Aug 4.
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 ,'-dioxide/Sc 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.
手性色满酮内酯是一类具有重要生物活性的天然产物。我们报道了丁烯内酯与2-酯基取代色酮的直接非对映和对映选择性烯醇式共轭加成反应。在低至1 mol%的手性二醇/Sc络合物、3 Å分子筛和催化量的六氟异丙醇（HFIP）存在下，该转化反应进行顺利。迈克尔受体的范围包括不同位置的各种取代色酮，还原后得到的所需色满酮内酯具有良好的收率和非对映选择性，以及优异的对映选择性（高达99% ee）。该策略可用于简洁合成布氏内酯C和戈尼内酯A、C和G。
