Bera Nabakumar, Samanta Shantanu, Sarkar Debayan
Department of Chemistry, National Institute of Technology, Rourkela, Rourkela769008, India.
J Org Chem. 2021 Dec 3;86(23):16369-16395. doi: 10.1021/acs.joc.1c01758. Epub 2021 Nov 4.
Synthesis of β-hydroxyenones and its application toward development of tetrahydro-4-pyran-4-one in an atom-economic fashion is limited. This manuscript describes a ruthenium-catalyzed atom-economic coupling of pent-2-yne-1,5-diols and Michael acceptors as an efficient route for the synthesis of β-hydroxyenones with excellent yields and high regioselectivity. The β-hydroxyenones further undergo a 6- cyclization under acid-catalyzed conditions to deliver the tetrahydro-4-pyran-4-ones with high diastereoselectivity. An intramolecular aldol condensation under mild basic conditions and palladium-catalyzed oxidative aromatization was developed for the synthesis of hexahydro-6-isochromen-6-ones and isochromanols, respectively, from highly substituted tetrahydro-4-pyran-4-ones with excellent yield and diastereoselectivity. Overall, this work demonstrates the synthetic potential toward the synthesis of oxacycles like tetrahydro-4-pyran-4-ones, hexahydro-6-isochromen-6-ones, and isochromanols via an atom-economic catalysis.
β-羟基烯酮的合成及其以原子经济方式用于开发四氢-4-吡喃-4-酮的应用受到限制。本手稿描述了钌催化的戊-2-炔-1,5-二醇与迈克尔受体的原子经济偶联，这是一种以优异产率和高区域选择性合成β-羟基烯酮的有效途径。β-羟基烯酮在酸催化条件下进一步进行6-环化反应，以高非对映选择性得到四氢-4-吡喃-4-酮。分别开发了在温和碱性条件下的分子内羟醛缩合反应和钯催化的氧化芳构化反应，用于从高度取代的四氢-4-吡喃-4-酮合成六氢-6-异色满-6-酮和异色满醇，产率和非对映选择性优异。总体而言，这项工作展示了通过原子经济催化合成四氢-4-吡喃-4-酮、六氢-6-异色满-6-酮和异色满醇等含氧杂环化合物的合成潜力。
