Tetrahedron

Synthesis of C 2-symmetric chiral crown ethers by lipase-catalyzed reactions

M Nakamura, T Taniguchi, N Ishida, K Hayashi…

Index: Nakamura, Misako; Taniguchi, Takuya; Ishida, Naohisa; Hayashi, Keishi; Muraoka, Masahiro; Nakatsuji, Yohji Tetrahedron, 2011 , vol. 67, # 48 p. 9298 - 9304

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Citation Number: 5

Abstract

Kinetic resolution of a racemic mixture of C2-symmetric 18-crown-6 diols (rac-1a) and 15- crown-5 diol (rac-1c) was achieved by lipase-catalyzed acetylation. The enantiomeric excess of the chiral crown diols (95% ee and 82% ee) was determined by 1H NMR spectroscopy, using (R)-(+)-1-(1-naphthyl) ethylammonium hydrochloride as a shift reagent. The C2-symmetric chiral 15-crown-5 diol (> 95% ee) was also obtained by kinetic ...