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

YILMAZ M., Yakut M., Pekel A. T.

SYNTHETIC COMMUNICATIONS, vol.38, no.6, pp.914-927, 2008 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 38 Issue: 6
  • Publication Date: 2008
  • Doi Number: 10.1080/00397910701845456
  • Journal Name: SYNTHETIC COMMUNICATIONS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.914-927
  • Kocaeli University Affiliated: Yes

Abstract

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.