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The addition of butyllithium at -100 °C to -bromoalkyl ethers of o-bromophenol (and its congeners) led to preferential exchange of the aryl bromine at position 2. The resulting organolithium reagents, under suitable conditions, cyclized to afford 2,3-dihydrobenzofurans (6), 3,4-dihydro-2/f-l-benzopyrans (13), or 2,3,4,5-tetrahydro-l-benzoxepins (16) in good yields, but less satisfactory results were obtained with the intermediate expected to produce 8-methyl-3,4,5,6-tetrahydro-2ff-l-benzoxocin (19). -Bromoethyl and -bromopropyl ethers of suitable dibromophenols were treated successively with 2 equiv of butyllithium and an electrophile to yield derivatives of 6 and 13.

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