Lipase-catalyzed transesterification in organic solvents: Preparation and enantiodifferentiation of optically enriched 4(5)-alkylated 1,4(1,5)-olides

The catalytic activity of lipases toward hydroxy fatty acids—A review

“…In addition, the rate and extent of estolide synthesis from o>HFA and their lactones were increased at elevated temperatures (13,26,27). However, for 7-and ~5-1actonization, room temperature proved to be quite adequate (5,7,9,11,(37)(38)(39).…”

“…For 7-and ~5-1actonization, substrate concentration is a less significant factor; moreover, 7-and 5-hydroxy acyl group concentrations between 3.5 and 250 mM yielded lactone as the major product (5,7,9,(37)(38)(39).…”

“…HFA were not used as substrate to avoid spontaneous lactonization, which would lower the reaction's enantioselectivity. Huffer and Shrier (9) found that even 7-and ~hydroxy acid methyl-and ethyl-esters spontaneously lactonized to a slight degree. They also discovered hydroxy acid propyl-and isopropyl-esters did not lactonize spontaneously, but that only the former was a suitable substrate for PPL (9).…”

“…Huffer and Shrier (9) found that even 7-and ~hydroxy acid methyl-and ethyl-esters spontaneously lactonized to a slight degree. They also discovered hydroxy acid propyl-and isopropyl-esters did not lactonize spontaneously, but that only the former was a suitable substrate for PPL (9). It is reported that even heat-denatured Pseudomonas lipase can catalyze lactonization from a 8-HAE, but with no enantioselectivity (11).…”

“…It is reported that even heat-denatured Pseudomonas lipase can catalyze lactonization from a 8-HAE, but with no enantioselectivity (11). y-Lactonization of hydroxy acyl groups with carbon length of 6-8 yielded high values of ee for both product (eep) and remaining substrate (ees), but eep declined when the chainlength was increased from 8 (9). Yamada et al ill) found that the enantioselectivity of Pseudomonas lipase toward 5-1actonization improved when the lipase was immobilized, and Triton surfactant was added.…”