138249-06-6Relevant articles and documents
Enzyme-mediated enantioselective hydrolysis of 1,2-diol monotosylate derivatives bearing an unsaturated substituent
Matsumoto,Oohana,Hashimoto,Usuda,Shimoda,Ohshima,Suzuki,Togawa
, p. 3981 - 3988 (2018)
We have succeeded in the easy preparation of optically active 1,2-diol monotosylates bearing an unsaturated substituent via enzymatic hydrolysis. Lipase PS quickly catalyzes the hydrolyses of 2-acetoxybut-3-enyl tosylate, which has a double bond, and 2-acetoxybut-3-ynyl tosylate, which has a triple bond, with excellent enantioselectivity to afford the corresponding optically active compounds. The reaction is also applicable to acetates with a longer chain, which has a double bond at the terminus. To demonstrate the applicability of this method, enantiomerically pure (R)-massoialactone, a natural coconut flavor, has been synthesized from racemic 2-acetoxypent-4-enyl tosylate in several steps. Furthermore, the enzyme can recognize the stereochemistry of olefins, and the (Z)-alkenyl structure is more suitable for the enantioselective hydrolysis than the (E)-isomer.
Protected hydroxy method for alcohol-ester separation
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, (2008/06/13)
A process is disclosed for the isolation of an enantiomerically enriched alcohol from a first mixture of an enantiomerically enriched alcohol and an enantiomerically enriched ester. The process includes the steps of: (a) contacting the mixture with a reagent capable of reacting with the hydroxy function of the alcohol, without the loss of optical purity, so as to produce a second mixture containing a base stable derivative of the enantiomerically enriched alcohol and the unreacted ester; (b) contacting the second mixture with a base capable of reacting with the ester so as to produce a third mixture containing a compound more volatile than the base stable derivative of the alcohol; (c) removing the volatile compound from the third mixture; and (d) converting the base stable derivative of the alcohol back to the enantiomerically enriched alcohol, without the loss of optical purity.