The utility of the dehalogenation–deetherification sequence for the proof of structure of methoxyhalocyclohexanols and methoxyhalocyclopentanols. Synthesis of the cis- and trans-2- and -3-methoxy-cyclohexanols and -cyclopentanols

Abstract

An unequivocal proof of structure for the methoxychlorocyclopentanols (I′c–IV′c) was obtained by deetherification with 68% hydrobromic acid at 65–70°, followed by hydrogenolysis with Raney nickel and hydrogen, to the 1,2- and 1,3-cyclopentanediols, in the same manner as the methoxybromocyclohexanols (I–IV) were converted into the 1,2- and 1,3-cyclohexanediols. Hydrogenolysis of the methoxybromocyclohexanols and the methoxychlorocyclopentanols provided stereospeciflc syntheses for the cis- and trans-2- and -3-methoxycy-clohexanols and -cyclopentanols in 80–97% yields. Deetherification of the latter compounds with 68% hydrobromic acid gave the corresponding 1,2- and 1,3-cyclohexanediols and 1,2-cyclopentanediols in 70–90% yields, but only 5–7% yields of the 1,3-cyclopentanediols. For the proof of structure of methoxyhalocyclanols, deetherification should therefore precede, rather than follow, dehalogenation.

Application of photoelectron spectroscopy to intramolecularly hydrogen-bonded systems. Part III. The photoelectron spectra of cis and trans 2-substituted cyclopentanols and cis and trans 2-substituted cyclohexanols

“…Methylation of the cis isomer by the Eschweiller-Clarke procedure (8) afforded cis-2-(N,N-dimethylamino)cyclohexanol while the corresponding tr.atls isomer was produced by opening of cyclohexene oxide with dimethylamine (9). rratls-2-Methoxycyclohexanol, and rrntls-2-methoxycyclopentanol were quantitatively prepared by the sulfuric acid catalysed opening of the corresponding epoxides in anhydrous methanol and gave physical properties which compared well with those published (10,11). The trotis isomers were converted into the corresponding cis isomers by the method of Buck er al.…”

Regio- and stereoselectivity in the solvomercuriation and intramolecular alkoxymercuriation of cyclic unsaturated alcohols

“…Among the reaction products, 3-methoxycyclohexanol, 24 2-methoxy-2-methylcyclohexanol, 25 3-methoxy-3-methylcyclohexanol, 25 3-methoxy-3,5-dimethylcyclohexanol, 25 3methoxycyclopentanol, 26 (3-methoxycyclohexane)methanol, 27 6-oxabicyclo[3.2.1]octane, 28 1-methyl-…”

Reaction of trans-2-Acylaminocyclanols with Thionyl Chloride

“…D,L-trans-2-Aminocyclopentanol was prepared by the ammonolysis of 1,2-epoxycyclopentane (27) following the method used by Hawkins and Bannard (24) for preparation of the cyclohexane analogue, except that it was found necessary to extend the heating period to 4 h. The substance was obtained as a colorless oil, b.p. 65" at 1.5 mm, nD25 1.4920, in 81.5% yield.…”