Structure versus enantioselectivity in Pseudomonas cepacia lipase catalysed transesterifications. Enantioselective acylations of primary 2-methylalcohols

✍ Scribed by Ba-Vu Nguyen; Ove Nordin; Carin Vörde; Erik Hedenström; Hans-Erik Högberg

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 257 KB
• Volume: 8
• Category: Article
• ISSN: 0957-4166
• DOI: 10.1016/s0957-4166(97)00051-7

✦ Synopsis

The enantioselectivities of lipase from Pseudomonas cepacia (Amano PS) towards a series of primary 2-methyl-oo-(2-thienyl)alkanols using vinyl acetate as the acyl donor in transesterifications in organic solvents have been studied. It was found to be important to place the thiophene ring in the correct position in the chain. In terms of enantioselectivity, we found that the number of methylene groups between the stereogenic centre and the aromatic ring in chiral t~-aryl-2-methylalkanols ought to be one. @ 1997 Elsevier Science Ltd Enantiomerically pure primary 2-methylalkyl derivatives are useful building blocks in natural product synthesis. | For the preparation of these, the thiophene ring can be exploited either as a masked alkyl chain (via Raney-nickel reduction) 2a-c or as a masked acid (via RuCl3-NalO4-oxidation), 2a the acid group of which can subsequently be transformed by elongation into an alkyl chain. 2d