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Why must Grignard reagents be prepared and handled in scrupulously dry conditions?
AWater makes the reagent more reactive
BMoisture catalyses decomposition by oxygen
CRMgX reacts violently with any source of proton (water, alcohol, amine) → R-H + Mg(OH)X, destroying the reagent
DWater dissolves the magnesium
Answer & Solution
Correct answer: C. RMgX reacts violently with any source of proton (water, alcohol, amine) → R-H + Mg(OH)X, destroying the reagent
RMgX is a **strong base** + nucleophile. Any acidic proton (water, alcohol, amine, terminal alkyne) protonates the R group → R-H + Mg(OH)X. So even traces of moisture destroy the reagent. Note: this is a useful method to convert R-X → R-H (Grignard + H₂O).
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