Williamson Ether Synthesis with Phenols at a Tertiary Stereogenic Carbon: Formal Enantioselective Phenoxylation of β-Keto Esters.
The enantioselective formation of α-aryloxy-β-keto esters is described for the first time. Lewis acid catalyzed enantioselective chlorination of β-keto esters and subsequent SN 2 reactions with phenols yielded α-aryloxy-β-keto esters with up to 96% ee. Favorskii rearrangement of α-chloro-β-keto esters was also found to give 1,2-diesters with slightly reduced enantiopurity.
Department of Environmental and Life Sciences, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, 441-8580 (Japan). shiba@ens.tut.ac.jp.
Kazutaka
K
Shibatomi
Department of Environmental and Life Sciences, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, 441-8580 (Japan).
Manato
M
Kotozaki
Department of Environmental and Life Sciences, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, 441-8580 (Japan).
Nozomi
N
Sasaki
Department of Environmental and Life Sciences, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, 441-8580 (Japan).
Ikuhide
I
Fujisawa
Department of Environmental and Life Sciences, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, 441-8580 (Japan).
Seiji
S
Iwasa
asymmetric synthesis; enantioselectivity; nucleophilic substitution; phenoxylation; synthesis design