| abstract |
L-(-)-carnitine is prepared from D-(+)-carnitinamide by (a) reacting D-(+)-carnitinamide in an acid medium with a straight or branched chain aliphatic alcohol thereby forming D-(+)-carnitine ester, (b) acylating the D-(+)-carnitine ester with an anhydride R2O, thereby forming an acylated ester intermediate, (c) acid hydrolyzing the ester group of the acyl carnitine ester thereby obtaining acyl D-(+)-carnitine, (d) lactonizing the acyl D-(+)-carnitine to a lactone of L-(-)-carnitine, and (e) reacting the lactone with base thereby forming L-(-)-carnitine. |