- Synthesis of 2,3-dihydro-4H-furo[3,2-c] chromen-4-ones and 2,3-dihydronaphtho[2,3-b]furan-4,9-diones by the radical cyclizations of hydroxyenones with electron-rich alkenes using manganese(III) acetate
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We have obtained dihydrofurans 3a-j in the radical cyclization of 4-hydroxycoumarin 1a and 2-hydroxy-1,4-naphtoquinone 1b with electron rich alkenes 2a-i by manganese(III) acetate. Methods A and B, which have different molar ratios were studied comparatively in these reactions, and we observed that method B (molar ratio 2:1:3) gave the best results. Treatment of 4-hydroxycoumarin 1a and electron rich alkenes 2a-e gave 2,3-dihydro-4H-furo[3, 2-c]chromen-4-ones 3a-e in 36-86% yields by the method B. Under the same conditions, the reactions of 2-hydroxy-1,4-naphtaquinone 1b with conjugated alkenes 2b and 2f-i afforded 2,3-dihydronaphtho[2,3-b]furan-4,9-diones 3f-j in an excellent yields. Copyright Taylor & Francis Group, LLC.
- Yilmaz, Mehmet,Yakut, Mehtap,Pekel, A. Tarik
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p. 914 - 927
(2008/09/17)
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