Enzymes in Organic Synthesis, 11. Enantioselective Lactonization of Methyl 3,5-Dihydroxyalkanoates. — An Access to (3R,5S,6E)-3-Hydroxy-7-phenyl-6-hepten-5-olide by Enzyme-Catalyzed Kinetic Resolution in Organic Solvents
✍ Scribed by Henkel, Birgitta ;Kunath, Annamarie ;Schick, Hans
- Publisher
- John Wiley and Sons
- Year
- 1992
- Tongue
- English
- Weight
- 280 KB
- Volume
- 1992
- Category
- Article
- ISSN
- 0947-3440
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✦ Synopsis
Abstract
By enzyme‐catalyzed intramolecular transesterification methyl (±)‐(3__R__*,5__S__*,6__E__)‐3,5‐dihydroxy‐7‐phenyl‐6‐heptenoate (rac‐4) can be enantioselectively converted into the δ‐lactone 5. An enantiomeric excess of 80% was obtained by Pancreatin in diethyl ether at ambient temperature. Repetition of the enzyme‐catalyzed lactonization with enantiomerically enriched 3,5‐dihydroxy ester 4/ent‐4 enhanced the e.e. to >99%. Lipases of Pseudomonas and Candida sp. 382 tested in eight organic solvents were less efficient. The absolute configuration of 5, obtained as the major enantiomer in all experiments, has been determined by its conversion into the known (—)‐goniothalamin (6).