LEAD TETRAACETATE .6. STEREOCHEMICAL STUDIES ON FORMATION OF BICYCLIC ETHERS FROM ALICYCLIC PRIMARY ALCOHOLS

The reactions of lead tetraacetate with 2-cyclohexylethanol, 3-cyclohexylpropanol, 2-eyclopentylethanol, and 3-cyclopentylpropanol were studied to determine the stereochemistry of the tetrahydrofurans formed. The oxidation of 2-cyclohexylethanol yielded both cis- and trans-7-oxabicyclo [4.3.0] nonanes, while 2-cyclopentylethanol yielded only the cis isomer of 2-oxabicyclo [3.3.0] octane. The oxidation of 3-cyclohexylpropanol yielded an oxaspiran, 1-oxaspiro [4.5] decane, in low yield, while the oxidation of 3-cyclopentylpropanol yielded a saturated oxaspiran, 1-oxaspiro [4.4] nonane, and an unsaturated oxaspiran, 1-oxaspiro [4.4] non-6-ene. The oxymercuration-demercuration of 2-(2-cyclohexenyl)ethanol (18) and 2-(2-cyclopentenyl)ethanol (19) yielded isomerically pure cis-7-oxabicy clo [4.3.0] nonane (2) and cis-2-oxabicyclo [3.3.0] octane (9). © 1969, American Chemical Society. All rights reserved.