Herstellung enantiomerenreiner Sulfoxide aus Milchsäure und 3-Hydroxybuttersäure: Isopropenyl-tolyl-sulfoxid und 2-(Phenylsulfinyl) acrylester
作者:Richard Breitschuh、Dieter Seebach
DOI:10.1055/s-1992-26328
日期:——
Preparation of Enantiomerically Pure Sulfoxides from Lactic Acid and 3- Hydroxybutyric Acid. Isopropenyl Tolyl Sulfoxide and 2-(Phenylsulfinyl) acrylate The EPC-synthesis of sulfoxides from readily available starting materials ("chiral pool") is demonstrated for the first time. Cyclic and open-chain thioethers derived from lactic and 3-hydroxybutyric acid are oxidized to sulfoxides, and the resulting products isolated in diastereomerically and enantiomerically pure form. Simple, large-scale conversions lead to methyl (S)-2-(phenylsulfinyl)acrylate and to (R)-isopropenyl tolyl sulfoxide from the corresponding (S)-lactate. Oxidation with tert-butyl hydroperoxide of chiral P-tolylthio-substituted propanols and butanols catalyzed by the addition of 1 % bis(2,4-pentadione)oxyvanadium(IV) (VOacac2) is diastereoselective (2:1 to 5.5: 1).
以乳酸和 3- 羟基丁酸为原料制备对映体纯硫醚。异丙烯基甲苯基亚砜和 2-(苯基亚磺酰基)丙烯酸酯 首次证明了用易获得的起始材料("手性池")进行亚砜的 EPC 合成。从乳酸和 3- 羟基丁酸中提取的环状和开链硫醚被氧化成硫醚,并分离出非对映和对映体纯的产物。通过简单、大规模的转化,可以从相应的(S)-乳酸酯制备出(S)-2-(苯基亚磺酰基)丙烯酸甲酯和(R)-异丙烯酰基甲苯亚砜。在加入 1 % 双(2,4-戊二酮)氧钒(IV) (VOacac2) 催化下,手性 P-甲苯硫代丙醇和丁醇与叔丁基过氧化氢的氧化反应是非对映选择性的(2:1 至 5.5:1)。