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反應(yīng)機(jī)理 四氧化鋨對烯烴進(jìn)行[3+2]環(huán)加成，生成五元環(huán)鋨酸酯中間體,，然后水解得到相應(yīng)的順式鄰二醇,。水解后的鋨酸被助氧化劑NMO氧化得到四氧化鋨，實(shí)現(xiàn)催化循環(huán),。因此反應(yīng)通常在含水體系中進(jìn)行,。水解步驟該催化循環(huán)的限速步驟。
【https://cheminfographic./2018/04/16/95-upjohn-dihydroxylation-1976/】 反應(yīng)實(shí)例
【Org. Biomol. Chem., 2003,1, 2173-2186】
(2S,3R,4S,5S)-5-Azidotetrahydro-2-methoxy-6-methyl-2H-pyran-3,4-diol (16a). To a 2-methyl-2-propanol/acetone (22.8 mL, 1:1 (v/ v)) solution of allylic azide 15a (1.92 g, 11.4 mmol) at 0 °C was added a solution of N-methylmorpholine N-oxide/water (50% w/v, 11.4 mL). Crystalline OsO4 (29 mg, 1 mol %) was added, and the reaction was allowed to stir for 18 h. The reaction mixture was quenched with 50 mL of saturated Na2S2O3 solution, extracted with EtOAc (3 × 200 mL), dried (Na2SO4), concentrated under reduced pressure, and then purified using silica gel flash chromatography eluting with 50% EtOAc/hexane to afford diol 16a (2.13 g, 10.9 mmol, 96%) 【J. Org. Chem. 2008, 73, 5211–5220】
【Tetrahedron, 2008, 64, 304-313】
【Chem. Commun., 2013, 49, 6806-6808 】 參考資料 一,、化學(xué)空間：https://cn./reactions/%E6%B0%A7%E5%8C%96%E5%8F%8D%E5%BA%94/2014/03/%E5%9B%9B%E6%B0%A7%E5%8C%96%E9%94%87%EF%BC%88%E6%B0%A7%E5%8C%96%EF%BC%89.html 二,、ReactionFlash：Upjohn dihydroxylation 相關(guān)反應(yīng) |
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