Sistemas Pi Delocalizados

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292 Chapter 14 DELOCALIZED Pi SYSTEMS: INVESTIGATION BY ULTRAVIOLET AND VISIBLE SPECTROSCOPY H product 57. Any allylic hydrogen may be lost from the intermediate cation (arrows): CH₃ CH₃ CH₃ H CH₂ H CH₃ CH₃ -H+ CN 0 CH₃ 58. (a) 7 + (b) CCH₃ (c) COCH₃ NC + + 2 " CH₃ O 59. (a) Identify the bonds in the products formed in the Diels-Alder Then work backward to the starting molecules. 0 + 0 0 + diene dienophile (b) See above. (c) B is the endo adduct and is favored. as is expected for the typical Diels-Alder process.