130670-50-7Relevant articles and documents
Enzymes in Organic Synthesis. 4. Investigation of the Pancreatin-Catalyzed Acylation of cis-Cyclopent-2-ene-1,4-diol with Various Trichloroethyl and Vinyl Alkanoates
Theil, Fritz,Schick, Hans,Lapitskaya, Margarita A.,Pivnitsky, Kasimir K.
, p. 195 - 200 (2007/10/02)
During the pancreatin-catalyzed acetylation of the meso-diol 1 with 2,2,2-trichloroethyl acetate (2a) in tetrahydrofuran/triethylamine, the enantiomeric monoacetates 3a and ent-3a are formed at nearly equal rates. ent-3a is rapidly acetylated in a second enzyme-catalyzed step, forming 4a, whereas 3a resists further enzymatic acetylation.Thus, the monoacetate 3a can be obtained in 48 percent yield with an enantiomeric excess (e.e.) of more than 99 percent. 2,2,2-Trichloroethyl propanoate and butanoate give the corresponding monoacylation products even in slightly better yields, whereas the octanoate affords the monoacylation product with a lower enantiomeric excess. 2,2,2-Trichloroethyl monochloroacetate provides the monoacylation product in a 40 percent yield with an e.e. of 90 percent.The dichloroacetate, however, affords the diacylation product exclusively in an enzyme-independent chemical reaction.With the 2,2,2-trichloroethyl esters of isobutyric, phenylacetic, and benzoic acid no transesterification could be achieved within 24 hours.The application of vinyl acetate, however, represents a significant improvement in the synthesis of enantiomerically pure monoacetate 3a from meso-diol 1.
