Dipotassium salts of 2,2¢-dihydroxybiphenyl derivatives underwent palladium(0) catalyzed regioselective allylation by sulfonic esters (mesylates, tosylates) of 1-ethenylcyclopropanol to produce, in good yields, 2,2¢-bis(cyclopropylideneethoxy)biphenyls, which are of biological interest. Whilst the tetrapotassium salt of 2,2¢,6,6¢-tetrahydroxybiphenyl, formed the triadduct 2,2¢-tris(cyclopropylideneethoxy)hydroxybiphenyl as its main product. An unexpected palladium-induced rearrangement of the monoadducts 2-(2cyclopropylideneethoxy)-2¢-hydroxybiphenyl derivatives into the 2-[2-(1-ethenylcyclopropyloxy)]-2¢-hydroxybiphenyl derivatives occurred; while the minor diastereomer of the monoadduct 2-[(2-cyclopropylidene-1-trimethylsilyl)ethoxy]-6,6-dimethoxy-2¢hydroxybiphenyl upon standing in CDCl 3 , underwent Claisen rearrangement into the 2,2¢-dihydroxy-6,6¢-dimethoxy-3-(2-trimethylsilylethenyl)cyclopropylbiphenyl.

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