ISSN:
0170-2041
Schlagwort(e):
Enzymes
;
Pentanedioic anhydride, 2-methyl
;
Alcoholysis, enantio- and regioselective
;
Esterification sequential
;
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
The enzyme-catalyzed sequential esterification of (±)-2-methylpentanedioic anhydride (rac-1) with 2-methylpropanol in diethyl ether afforded a 1:1 mixture of 1-(2-methylpropyl) 5-hydrogen (S)-4-methylpentanedioate (ent-2) with an enantiomeric excess of 88% and 1-(2-methylpropyl) 5-hydrogen (R)-2-methylpentanedioate (3) with an e.e. of 99% besides a considerable amount of the diester ent-4. Exploiting the ability of the enzymes Novozym and SP 382 to differentiate between the two enantiomers and to catalyze the alcoholysis of both enantiomers with opposite regioselectivity, we reduced the resolution of rac-1 to a simple chromatographic separation of enantiomerically enriched regioisomeric monoesters. The high optical purity of monoester 3 could be achieved due to the fast conversion of its enantiomer into the diester ent-4. Via reduction with lithium borohydride the monoesters ent-2 and 3 were converted into the corresponding δ-valerolactones ent-5 and 6.
Zusätzliches Material:
1 Tab.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/jlac.199419941011
