CYCLOHEXANE COMPOUNDS: III. THE 1-METHOXY- AND 1-ETHOXY-2-HYDROXY-3-BROMOCYCLOHEXANES

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Abstract
1α-Methoxy- 2β - hydroxy- 3α-bromocyclohexane and 1α-methoxy-2α-hydroxy-3β-bromocyclohexane have been prepared by the action of hydrobromic acid on 1β-methoxy-2α,3α-epoxycyclohexane and 1α-methoxy-2α,3α-epoxycyclohexane respectively. Assignment of stereochemical configuration to 1α-methoxy-2β-hydroxy-3α-bromocyclohexane was made by catalytic denomination of the phenyl- and 1-naphthyl-urethanes to derivatives of 2β-methoxy-1α-cyclohexanol. An alternative proof of structure was obtained by de-etherification of the bromohydrin to 3α-bromo-1α,2β-cyclohexanediol, which was catalytically debrominated to 1α,2β-cyclohexanediol and oxidized via periodate to 2-bromoadipaldehyde, isolated as the bis-2,4-dinitrophenylhydrazone. The structure of 1α-methoxy-2α-hydroxy-3β-bromocyclohexane was established by de-etherification to 3β-bromo-1α,2α-cyclohexanediol, which was oxidized by periodate 10 times more rapidly than its isomer. The corresponding ethoxy compounds were prepared and their structures were elucidated in a completely analogous manner.