Production of S -3-Phenoxybenzaldehyde Cyanohydrin SCMB

The largest commercial production of a chiral cyanohydrin is that of (S)-3-phenoxy-benzaldehyde cyanohydrin, which is used for the production of synthetic pyrethroids, i.e., coupling of a chiral pyrethrum acid chloride derivative with the (S)-configured cyanohydrin yields insecticides, which represent a valuable market. 

The production of the chiral cyanohydrin that is used for pyrethroid synthesis as depicted in Fig. 9 is performed using recombinant (S)-HNL from Hevea brasi-liensis. Under the above-mentioned boundary conditions a space-time yield of 1000 g/L/d (ee = 98.5%) is routinely reached. Fig. 10 shows a selection of products, which are currently on the market. 

Of these products, Deltamethrin is produced from racemic CMB the chiral pyrethrum acid effects dynamic resolution of the cyanohydrin. 

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