Cycloaddition reactions of indenes. 2. Reactions with dimethyl acetylenedicarboxylate and maleic anhydride

…, V Kameswaran, LL Landucci

Index: Noland, Wayland E.; Kameswaran, Venkataraman; Landucci, Lawrence L. Journal of Organic Chemistry, 1980 , vol. 45, # 23 p. 4564 - 4572

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Citation Number: 11

Abstract

1H-Indenes (1) react with dimethyl acetylenedicarboxylate (DMAD), unlike maleic anhydride and other ethylenic dienophiles, without prior isomerization to 2H-indenes (2), giving a 1: l Diels-Alder adduct (6) formed with destruction of the aromaticity of the benzene ring. This intermediate, not isolated in the present work, appears to serve as the precursor for all further adducts. Thus, 1H-indene (la) and 1-methyl-lH-indene (lb), but not the more ...