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Reaction of o-(1,3-pentadienyl)-phenol 3 with 1,3-dichloro-2-phenylsulfonylpropane 2 in the presence of triethylamine gave o-(1,3-pentadienyl)-phenyl (2-phenylsulfonyl)-2-propenyl ether 4 in 91–100% yields, which underwent intramolecular Diels-Alder reactions to dord dibenzopyran derivatives.
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Yamamoto et al. (1996) studied this question.
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