Homolytic carbocyclization by use of a heterogeneous supported organotin catalyst. A new synthetic route to 2-alkoxytetrahydrofurans and. gamma.-butyrolactones

Y Ueno, K Chino, M Watanabe, O Moriya…

Index: Ueno, Yoshio; Chino, Kunitake; Watanabe, Masaru; Moriya, Osamu; Okawara, Makoto Journal of the American Chemical Society, 1982 , vol. 104, # 20 p. 5564 - 5566

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Citation Number: 217

Abstract

We found that bromoacetals (1) 5 cyclized to five-membered cyclic acetals (2) but not to six- membered ones under homolytic conditions. To a solution of 1 and a catalytic amount of azobisisobutyronitrile (AIBN)(1 mol%) in dry benzene was added dropwise an equivalent of tributyltin hydride at rmm temperature or in some cases at 50 OC in-30 min (eq 1; 0.25 M concentration