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Identify the correctly matched reaction(s) from the following: (I) C6H5-CHO + H-CHO + conc. NaOH -> C6H5-CH2OH + HCOONa (II) OHC-CH2-CO-CH3 + NaOH + I2 -> 2 HCOONa + CHI3 (III) Cyclohexanone + (i) H2N-NH2/H+ (ii) OH-/heat -> Cyclohexane (IV) HO-CH2-CH2-OH + PI3 (2 eq.) -> H2C=CH2

1. I and IV only
2. I, II and III only
3. I, II, III and IV
4. I, II and IV only

Correct answer: I and IV only

Solution

Reaction I (cross-Cannizzaro with HCHO as reductant) and reaction IV (vicinal diol -> diiodide -> alkene) are correctly matched. Reaction III is wrong because Wolff-Kishner gives cyclohexane (not cyclohexanol). Reaction II involves an aldehyde-ketone compound whose iodoform product distribution is ambiguous from the given structure.

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