College of Pharmacy , Seoul National University , 1 Gwanak-ro , Gwanak-gu , Seoul 08826 , Republic of Korea.
J Nat Prod. 2019 Apr 26;82(4):895-902. doi: 10.1021/acs.jnatprod.8b00986. Epub 2019 Feb 15.
The expedient synthesis of alphitolic acid (1) as well as its natural C-3-epimer and 2- O-ester derivatives was accomplished in a few steps from the readily commercially available betulin (9). A Rubottom oxidation delivered an α-hydroxy group in a stereo- and chemoselective manner. The diastereoselective reduction of the α-hydroxy ketone was key to accessing the 1,2-diol moiety of this class of natural products. Our concise and stereoselective synthetic protocol allowed the gram-scale synthesis of these natural products, which will facilitate future biological evaluations.
从商业上可获得的白桦脂醇（9）出发，经过几步反应，即可方便地合成阿朴菲酸（1）及其天然 C-3-差向异构体和 2-O-酯衍生物。Rubottom 氧化以立体和化学选择性的方式得到 α-羟基。α-羟基酮的非对映选择性还原是获得此类天然产物 1,2-二醇部分的关键。我们简洁且立体选择性的合成方案允许对这些天然产物进行克级规模的合成，这将有利于未来的生物学评价。
