The synthesis of optically pure (S)-5-formyl-4-hydroxy-screened (hydrolases). Using the chemoenzymatic approach from (R,S)-1, optically pure (S)-1 and after subjecting (S)-1 [2.2]paracyclophane (S)-3 (ee Ͼ 99 %) was achieved by a three-step chemoenzymatic procedure consisting of (i) to hydrolysis and finally to formylation (S)-3 was obtained.
As confirmed by chiral GC, hydrolysis and formylation took kinetic enzymatic resolution of (R,S)-4-acetoxy[2.2]paracyclophane (R,S)-1 to produce optically pure starting place without racemization. During the optimization of the enzymatical part of the synthesis a strong influence of both material, which after (ii) hydrolysis was subjected to (iii) stereoselective ortho-formylation with an overall yield of 51 the nature of the cosolvent and the pH of the buffer-phase on the enantioselectivity value E were observed. Using a %. All attempts to use a biocatalyst directly for the preparation of optically pure disubstituted [2.2]para-two-phase system consisting of diethyl ether and phosphate buffer an E value higher than 100 was achieved at a pH of cyclophanes failed because of either total lack of activity (bioreduction) or low enantioselectivities of the enzymes 7.0 and at room temperature.
[ ] Part of the planned Ph. D. thesis of D. P.
mined recently by activity staining experiments [13] . Because