1,3-Dienones and 2H-Pyran-2-ones from Soft α-Vinyl Enolization of β-Chlorovinyl Ketones: Defined Roles of Brönsted and Lewis Base
Hun Young Kim and Kyungsoo Oh*
*Center for Metareceptome Research, College of Pharmacy, Chung-Ang University, 84 Heukseok-ro, Dongjak, Seoul 156-756, Republic of Korea, Email: kyungsooohcau.ac.kr
H. Y. Kim, K. Oh, Org. Lett., 2015, 17, 6254-6257.
DOI: 10.1021/acs.orglett.5b03265 (free Supporting Information)
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In the eliminative reaction of (E)-β-chlorovinyl ketones, Et3N as Brönsted base effected a soft α-vinyl enolization to afford cumulenol intermediates. Addition of a catalytic amount of a Lewis base (PPh3) initiated isomerization to 1,3-dienones in high yields. Furthermore, the introduction of a carbon-based nucleophile into the reaction mixture provided a highly efficient synthetic route to 2H-pyran-2-ones in one pot.
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