- Deracemization of α-aryl hydrocoumarins via catalytic asymmetric protonation of ketene dithioacetals
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An unprecedented catalytic asymmetric protonation of ketene dithioacetals is described. Various racemic α-aryl hydrocoumarin derivatives are transformed into enantioenriched dithioacetal-protected hydrocoumarins in the presence of a chiral Br?nsted acid catalyst. A newly developed phosphoric acid, featuring the 3,5-bis(pentafluorothio)phenyl (3,5-(SF5) 2C6H3) substituent, is introduced. The obtained products can be easily converted into either hydrocoumarins or the corresponding chromans via simple hydrolysis or hydrogenation, respectively.
- Lee, Ji-Woong,List, Benjamin
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p. 18245 - 18248
(2013/01/15)
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