The reaction of lead tetra-acetate with some unbranched α,ω-diols

Unbranched α,ω-diols are mainly converted by means of lead tetra-acetate in refluxing benzene to the corresponding ethers of di-α-tetrahydrofuryl, di-α-tetrahydropyryl and/or α-tetrahydrofuryl-α′-tetrahydropyryl type. Thus, 1,6-hexanediol affords cis-1,4-dioxaperhydropentalene (Ia) in 15·2% yield; 1,7-heptanediol affords 1,6-dioxaspiro[4.4]nonane (II) in 29·2% yield; 1,8-octanediol cyclizes to 1,6-dioxaspiro[4.5]decane (IIIa) in 39·3% yield; 1,9-nonanediol affords a mixture of di-α-tetrahydrofurylmethane (IV, 33·2%), 2-(α-tetrahydrofuryl)α′-tetrahydropyran (IVa, 3·7%) and 1,7-di-oxaspiro[5.5]undecane (IVb, 3·3%); 1,10-decanediol is oxidized to a mixture of 1,2-di-α-tetrahydrofurylethane (V, 27·2%), and threo- and erythro-α-tetrahydrofuryl-α′-tetrahydropyrylmethanes (Va, 4·3%); and 1,11-undecanediol affords, as main product, 1,3-di-α-tetrahydrofurylpropane (VI) in 40·1% yield, together with small amounts of four other ethers which were not identified