Sodium Hydroxide → HCID 54178952, Verbindung
Reaktionsgleichung
OP([O-])(O)=O.[K+].[C:7]([C:9]([C:18]1[CH:23]=[CH:22][C:21]([N+:24]([O-:26])=[O:25])=[CH:20][CH:19]=1)([CH2:16][CH3:17])[CH2:10][CH2:11][C:12]([O:14][CH3:15])=[O:13])#[N:8].[OH-].[Na+]>>[C:7]([C@:9]([C:18]1[CH:19]=[CH:20][C:21]([N+:24]([O-:26])=[O:25])=[CH:22][CH:23]=1)([CH2:16][CH3:17])[CH2:10][CH2:11][C:12]([O:14][CH3:15])=[O:13])#[N:8]Komponenten
4
Reaktionsbedingungen
- Temperatur
- 37 °C
Versuchsvorschrift
A 1 l jacketed biotransformation vessel was charged with 0.05M KH2PO4, pH 7.5 (500 ml) and methyl 4-cyano-4-(4-nitrophenyl)hexanoate (20 g, 72 mmol). α-Chymotrypsin (ex. Aldrich; 4 g) was introduced and the mixture was agitated using an overhead stirrer. Temperature was maintained at 37° C. with the aid of a thermocirculator and the pH controlled by a probe linked to an autotitrator. The biotransformation was allowed to proceed until 18 ml of 1M NaOH had been added (equivalent to 50% conversion). This took about 68 hours, with addition of more α-chymotrypsin (1 g portions) after 24 hours and 50 hours. At this point, the biotransformation was quenched by the addition of NaCl (50 g) and the resulting mixture was extracted with diethyl ether (500 ml×3). The extracts were pooled, dried and concentrated under reduced pressure, yielding 10 g (50%) of (R)-methyl 4-cyano-4-(4-nitrophenyl)hexanoate, enriched in the (R)-enantiomer, 70% ee by chiral HPLC analysis.