Preparative Bioorganic Chemistry, XI Preparation of the Enantiomers of Paraconic Acid Employing Lipase-Mediated Asymmetric Hydrolysis of Prochiral Diacetates as the Key Step
✍ Scribed by Mori, Kenji ;Chiba, Naoki
- Book ID
- 102901280
- Publisher
- John Wiley and Sons
- Year
- 1989
- Tongue
- English
- Weight
- 605 KB
- Volume
- 1989
- Category
- Article
- ISSN
- 0947-3440
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✦ Synopsis
Paraconic acid / Lipase / Asymmetric hydrolysis / Prochiral diacetates (5')-( -)-Paraconic acid '
) (1) was previously employed by one of us as the starting material for the synthesis of (3R)-( -)-A-factor3), the inducer of streptomycin biosynthesis in inactive mutants of Streptomyces griseus4). The enantiomers of 1 can be prepared by resolving the racemate with (R)-(+)-a-phenethylamine or its (S) isomer5). However, this standard method was rather inefficient to give (S)-(-)-1 in ca. 3% yield from (&)-I even by an experienced practitioner3'.
To circumvent this problem, we became interested in preparing optically active paraconic acid or its equivalents by simple enzymatic methods. A promising such method for our purpose is the use of esterase or lipase to achieve asymmetric hydrolysis of a prochiral diester. This strategy was first used by Sih et aL6) in their synthesis of the enantiomers Scheme 1. Synthetic plan for paraconic acid (S)-(-)-1 (JR)-(-)-A-factor ' ) In chloroform.b, pH = 7.
.I-1 I