title: 1,3-Dienones and 2H-Pyran-2-ones from Soft α-Vinyl Enolization of β-Chlorovinyl Ketones: Defined Roles of Brönsted and Lewis Base.
abstract: The eliminative reaction pathways of (E)-β-chlorovinyl ketones were investigated in the presence of both Brönsted and Lewis bases. The Brönsted base, Et3N, effected the soft α-vinyl enolization of (E)-β-chlorovinyl ketones to [3]cumulenol intermediates; in turn, a catalytic amount of Lewis base, PPh3, initiated isomerization to provide 1,3-dienones in high yields. The introduction of a carbon-based nucleophile into the reaction mixture provided the highly efficient synthetic route to 2H-pyran-2-ones in one pot, where the carbon-based nucleophile generated by an extra equivalent of Brönsted base, Et3N, attacked the electrophilic [3]cumulenol intermediates to initiate cyclization to give 2H-pyran-2-ones.
authors.affiliation: Center for Metareceptome Research, College of Pharmacy, Chung-Ang University , 84 Heukseok-ro, Dongjak, Seoul 156-756, Republic of Korea.
authors.forename: Hun Young
authors.initials: HY
authors.lastname: Kim
authors.affiliation: Center for Metareceptome Research, College of Pharmacy, Chung-Ang University , 84 Heukseok-ro, Dongjak, Seoul 156-756, Republic of Korea.
authors.forename: Kyungsoo
authors.initials: K
authors.lastname: Oh
mesh_terms: D000438:Alcohols; D002384:Catalysis; D003500:Cyclization; D007659:Ketones / Q000138:chemical synthesis* / Q000737:chemistry; D058115:Lewis Bases / Q000737:chemistry*; D015394:Molecular Structure; D011753:Pyrones / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000438:Alcohols; D007659:Ketones; D058115:Lewis Bases; D011753:Pyrones