Pseudomonas cepacia lipase Subject

A recent synthesis of both (+)- and (-)-enantiomers of calystegine Aj has been achieved, commencing from the 6-azido derivative of meso-2-cycloheptene-1,4-diol [57]. The amine derived from this compound was protected as the benzyl carbamate (47) and subjected to asymmetrization using Pseudomonas cepacia lipase to give the mono-acetate (48). The product of this reaction was ... 

Another Bristol-Meyers Squibb process represents an enzymatic route for the production of side-chain precursors of Paclitaxel (33, Scheme 10) [69]. Racemic czs-azetidinone acetate (rac-31) is subjected to the hydrolytic treatment of Pseudomonas cepacia lipase (PCL), which is used in its immobilized form on polypropylene beads. Thus, (3R,4S)-acetate 31 can be obtained in high ee as well as the remaining alcohol 32. The process takes place in 150 1 reactors where 1.2 kg mc-31/batch can be resolved with a hydrolysis rate of 0.12 g/lh. Lowering the reaction temperature to 5 °C after full conversion causes (3R,4S)-31 subsequently to crystallize. Due to the immobilization, the enzyme can be reused for at least ten cycles without any loss of activity, productivity, or optical purity of the product. Paclitaxel is finally accessible by further chemical steps. 

Thus, benzylation of rraRS-3,3-diethoxy-l,2-bis(hydroxymethyl)cyclobutane (24)23aJ> to 25 (Scheme 3) was followed by hydrolysis to tra s-2,3-bis(benzyloxymethyl)-cyclobutanone (26).28 Reduction of 26 with LS-Selectride to ( )-(lo,2a,3p)-2,3-bis(benzyloxymethyl)cyclobutanol (27) occurred with no indication (by and NMR) of the diastereomeric alcohol 29 having been formed. Acetylation of 27 gave 28, which, when subjected to treatment with Pseudomonas cepacia lipase, yielded (+)-28 (>99% ee and (-)-27 (>99% ee ). The structural assignments for (+)-28 and (-)-27 were accomplished by conversion into the enantiomeric alcohols 30 and 31 and comparing the optical rotation data for each product with the reported values for these latter conqx>unds. 

Various cyclic esters have been subjected to hpase-catalyzed ring-opening polymerization. Lipase catalyzed the ring-opening polymerization of 4- to 17-membered non-substituted lactones.In 1993, it was first demonstrated that medium-size lactones, 8-valerolactone (8-VL, six-membered) and e-caprolactone (e-CL, seven-membered), were polymerized by lipases derived from Candida cylindracea, Burkholderia cepacia (lipase BC), Pseudomonas fluorescens (lipase PF), and porcine pancreas (PPL). °... 

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