3- Vinylbenzo thiophene, reaction with benzyne

Vinylbenzo[6]thiophene undergoes Diels-Alder reactions with benzyne,468 maleic anhydride,469 benzo[6]thiophene-1,1-dioxide,469 p-benzoquinone, and various 1,4-naphthaquinones.469,470 With quinones, the product depends on the reaction conditions. For... 

One example is the reaction with benzyne of 3-vinylbenzo[/ ]thiophene 102, prepared by dehydration of 2-(3-benzo[b]thienyl)ethanol, to give 11-thiabenzo[a]fiuorene 103 (65AJC1781). 

Benzyne in solution reacts as a dienophile Wittig (1957) first demonstrated this in the reaction of benzyne with furan. Corbett and Porter (1965) obtained further supporting evidence by isolating 1,4-addition products from benzyne with 1-vinylnaphthalene and 3-vinylbenzo[b]-thiophene Dilling (1966) did the same with styrene. 

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