Regioselective nucleophilic additions to cross-conjugated dienone system bearing beta-fluorine: a versatile approach to highly substituted 2-cyclopentenones.
[reaction: see text] 3-Fluoro-5-methylene-2-cyclopentenone is treated with appropriate nucleophiles and Lewis acids to undergo regioselective 1,2-addition, exocyclic 1,4-addition, and endocyclic 1,4-addition, leading to 3-substituted 4-methylene-2-cyclopentenones, 5-substituted 3-fluoro-2-cyclopentenones, and 3-substituted 5-methylene-2-cyclopentenones in good yields, respectively.
Ichikawa
J
J
Department of Chemistry, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. junji@chem.s.u-tokyo.ac.jp
Fujiwara
M
M
Miyazaki
S
S
Ikemoto
M
M
Okauchi
T
T
Minami
T
T
D003517:Cyclopentanes / Q000138:chemical synthesis*; D006845:Hydrocarbons, Fluorinated / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
D003517:Cyclopentanes; D006845:Hydrocarbons, Fluorinated; C013905:cyclopentenone