Organic letters

Photoinduced Electron Transfer Promoted Radical Ring Expansion and Cyclization Reactions of α-(ω-Carboxyalkyl) β-Keto Esters

K Nishikawa, T Ando, K Maeda, T Morita…

Index: Nishikawa, Keisuke; Yoshimi, Yasuharu; Maeda, Kousuke; Morita, Toshio; Takahashi, Ichiro; Itou, Tatsuya; Inagaki, Sho; Hatanaka, Minoru Journal of Organic Chemistry, 2013 , vol. 78, # 2 p. 582 - 589

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Citation Number: 13

Abstract

Photoinduced electron transfer (PET) promoted decarboxylation of α-(ω-carboxyalkyl) β-keto esters undergoes radical ring expansion and cyclization reactions. This mild and environmentally friendly method can provide one-carbon expanded γ-keto esters and bicyclic alcohols, and the product distribution is strongly dependent on the length of the alkyl chain containing the terminal carboxylate group.

~81%

~86%

~96%

~80%

Free-radical macrocyclization-transannular cyclization

[Porter,N.A.; Chang,V.H.; Magnin,D.R. Journal of the American Chemical Society, 1988 , vol. 110, p. 3554]

Many-membered Carbon Rings. X. Reduction of Diametric Diketo...

[Blomquist et al. Journal of the American Chemical Society, 1955 , vol. 77, p. 1804]