Hydroxy Acids by DKR Hydrolytic Enzymes Ruthenium-based Racemization Catalysts

Deracemization of Hydroxy Acids by DKR (Hydrolytic Enzymes + Ruthenium-based Racemization Catalysts) 

The use of the ruthenium catalysts is advantageous since it does not need the presence of a base as a co-catalyst. The presence of a base could induce racemization of the formed acetates by enoUzation. 

The same methodology was also applied to the DKR of (5-hydroxyesters. In the latter case, the reaction was carried out in tandem with an aldol reaction and the P-hydroxyester formed, after neutralization, underwent DKR using the immobilized lipase from Candida antarctica and a ruthenium catalyst [8]. 

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Scheme 13.2 Deracemization of a-hydroxy acids by DKR (hydrolytic enzymes + ruthenium-based racemization catalyst).

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