Birgitta Henkel

Enzyme-catalyzed lactonization of methyl (±)-(E)-3,5-dihydroxy-7-phenyl-6-heptenoates. - A comparison of the behaviour of syn- and anti-compounds

Abstract 3-Hydroxy lactones with a high enantiomeric excess were obtained by the lipase-catalyzed enantioselective lactonization of racemic syn - and anti -3,5-dihydroxy carboxylic esters. The (5 S )-lactones were formed predominantly from both diols with pancreatin as enzyme. The lipase from Candida sp . 382, however, catalyzed the preferential formation of the (5 S )-lactone only from the syn -diol. From the anti -diol the (5 R )-lactone was formed as the main enantiomer.

Synthesis of (3R,5S)-3-hydroxy-7-phenyl-6-heptyn-5-olide by an enantioselective enzyme-catalyzed lactonization of a racemic 3,5-dihydroxy ester

Abstract (3 R ,5 S )-3-Hydroxy-7-phenyl-6-heptyn-5-olide was obtained with a high enantiomeric excess by an enzyme-catalyzed enantioselective lactonization of the corresponding methyl (3 R * , 5 S * )-dihydroxyalkynoate followed by spontaneous crystallization.

Direct optical resolution of 3,5-substituted δ-valerolactones and related 3,5-dihydroxyvaleric methyl esters on modified amylose and cellulose chiral stationary phases

Abstract The optical resolution of 3,5-disubstituted lactones and related diol esters was carried out by HPLC on chiral stationary phases consisting of cellulose tris(3,5-dimethylphenylcarbamate), cellulose tris(4-chlorophenylcarbamate) and amylose tris(3,5-dimethylphenylearbamate) derivatives coated on macroporous silica using hexane-2-propanol and hexane-ethanol mobile phases. In most instances baseline separation could be achieved.