The aryl alkyl chlorohydrin shown is trans-configured. Treatment with one equivalent of NaOH gives an epoxide (intramolecular S_N2), and subsequent treatment with NaOMe in methanol opens that epoxide. Considering relative configuration only, which structure is the final product?

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JEE Advanced levelSingle correct optionDifficulty 3 of 3o3270

The aryl alkyl chlorohydrin shown is trans-configured. Treatment with one equivalent of $NaOH$ gives an epoxide (intramolecular $S X_{N} 2$ ), and subsequent treatment with $NaOMe$ in methanol opens that epoxide. Considering relative configuration only, which structure is the final product?

AStructure A
BStructure B
CStructure C
DStructure D

Answer: C

The compound is trans-2-chlorocyclohexanol (trans by the labels S,S). Hydroxide removes the OH proton, and the alkoxide displaces chloride from the back side (the OH and Cl must be anti), giving cyclohexene oxide. Methoxide then opens the epoxide by backside attack, so the OMe and OH are trans. The product is trans-2-methoxycyclohexanol (the cis isomer would need syn opening).

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The aryl alkyl chlorohydrin shown is trans-configured. Treatment with one equivalent of NaOH gives an epoxide (intramolecular SXN​2), and subsequent treatment with NaOMe in methanol opens that epoxide. Considering relative configuration only, which structure is the final product?

Answer: C

More questions on Epoxide and ether cleavage regiochemistry on drawn structures

The aryl alkyl chlorohydrin shown is trans-configured. Treatment with one equivalent of $NaOH$ gives an epoxide (intramolecular $S X_{N} 2$ ), and subsequent treatment with $NaOMe$ in methanol opens that epoxide. Considering relative configuration only, which structure is the final product?