See image — Alcohols Phenols and Ethers Chemistry Question

💡 Solution & Explanation

Step 1 – Concept: The reaction sequence involves (i) tosylation of an alcohol to give a tosylate (good leaving group), followed by (ii) reduction with LiAlH4. Step 2 – First reaction (TsCl, Pyridine, 25°C): 1-Tetralol (1,2,3,4-tetrahydronaphthalen-1-ol) reacts with tosyl chloride in pyridine at 25°C. This converts the –OH group into an –OTs (tosylate) group with retention of configuration. Product A is 1-tosyloxy-1,2,3,4-tetrahydronaphthalene. Step 3 – Second reaction (LiAlH4, Pyridine, 25°C): LiAlH4 is a strong hydride reducing agent. When it reacts with a tosylate (R–OTs), it performs an SN2 reaction, replacing the –OTs leaving group with a hydride (H–). This results in net replacement of –OH (via –OTs) with –H, effectively deoxygenating the alcohol. The product B is therefore 1,2,3,4-tetrahydronaphthalene (tetralin), which is a benzene ring fused to a fully saturated cyclohexane ring with no substituents. Step 4 – Why other options fail: (a) 1,2-Dihydronaphthalene would require elimination, not reduction/substitution. LiAlH4 does not cause elimination here under these mild conditions when a simple tosylate is present. (b) The structure shown appears to imply some substituent or unsaturation inconsistent with simple deoxygenation. (d) A chloro product would not form because LiAlH4 delivers hydride, not chloride; TsCl does not give a C–Cl bond at C1. Step 5 – Conclusion: The sequence TsCl/pyridine (tosylation) followed by LiAlH4 (SN2 reduction) converts the secondary alcohol into the corresponding C–H compound. The product B is 1,2,3,4-tetrahydronaphthalene (tetralin), which matches option (c). Therefore, the correct answer is C.