Ethyl hexanoate, hydrolysis

Initial scale up of the enzymatic resolution for production of kilogram quantities of (R)-2-amino-2-ethylhexanoic acid was performed in a batch process. The oil of ethyl 2-amino-2-ethyl-hexanoate was suspended in an equal volume of water containing the enzyme. The enantioselective hydrolysis of the ester proceeded at room temperature with titration of the produced acid by NaOH through a pH stat (Figure 6.4). 

Hammet and collaborators140, 141 studied in more detail the hydrolysis of aliphatic esters with a cation-exchange resins as catalyst. They found that replacement of 70% of the hydrogen ions in a crosslinked polystyrenesulfonic add by cetyl-trimethylammonium ions had a specifically favorable effect on the effectiveness of the remaining hydrogen ions for the hydrolysis of ethyl-n-hexanoate. From these findings, the important contributions of the hydrophobic forces, in addition to the electrostatic forces, is clearly demonstrated. 

Cordes, etal also employed poly-4-vinylpyridine alkylated with lauryl bromide and ethyl bromide (PVP-Ljj, 27) for the hydrolysis of p-nitrophenyl hexanoate (23,... 

There are several different ways in which a lactam precursor can be generated. An interesting but relatively specific synthesis is shown in reaction 8 and employs thiophene derivatives. Catalytic hydrogenation of bicyclic thiophene 2.69 gave 2-elhylhexahydroazepine-2-one [2.70) and acid hydrolysis gave 2-ethyl-7-amino-hexanoic acid, 2.77.33... 

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