Methyl hydrocinnamate

Hydrolysis of methyl hydrocinnamate is catalyzed by the enzyme chymotripsin. Data were obtained at 25 C with pH k7.6 and a constant enzyme concentration. These are of initial reaction rate, mol/1iter-sec, and corresponding initial substrate concentrations. Find the Michaelis-Menten constants. 

Methyl hydrocinnamate Ethyl hydrocinnamate Propyl hydrocinnamate Butyl hydrocinnamate... 

Mechanism 2 (the semibenzilic acid mechanism) looks better, but labeling studies show that the two C atoms a to the ketone become equivalent in the course of the reaction, which is consistent only with mechanism 1 (the electrocyclic mechanism). The rearrangement of a-chloro-o-phenylacctonc to methyl hydrocinnamate is also consistent only with the electrocyclic mechanism if the semibenzilic mechanism were operative, then methyl 2-phenylpropionate would be the product. 

The large scale preparation of (S)-2 [(tert-butylsulfonyl)-methyl]hydrocinnamic acid [(S)-4], a chiral building block in the synthesis of the potential rennin inhibitor Remikiren (not in use since it failed in the clinical phase), was performed via Subtilisin Carlsberg-catalyzed racemic resolution of the ester roc-3. The substrate was emulsified at 39-43 °C in 29% concentration in aqueous buffer and the pH was controlled using a 2-4 M NaOH solution. Work-up proved to be the rate-limiting step, nevertheless, the desired product could be isolated in 41.6% yield on a 100 kg scale. The product was obtained with excellent chemical (>99.5%) and enantiomeric (>99%) purity (Scheme 4.8). 

B. Wirz, S. Doswald, E. Kupfer, W. Wostl, T. Weisbrod, H. Estermann, Protease-Catalyzed Preparation of (S)-2-[(tert-butylsulfonyl)-methyl]-hydrocinnamic Acid for Rennin Inhibitor RO0425892, in H.-U. Blaser, E. Schmidt (Eds.), Asymmetric Catalysis on Industrial Scale, Wiley-VCH, Weinheim, 2004, pp. 385-398. 

Protease-Catalyzed Preparation of (S)-2-[(tert-Butylsulfonyl)methyl]-hydrocinnamic Acid... 

Methylhydrazine. See Methylhydrazine Methyl hydride. See Methane gas Methyl hydrocinnamate. See Methyl 3-phenylpropionate Methyl hydrogenated rosinate CAS 8050-13-3 8050-15-5 EINECS/ELINCS 232-476-2... 

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