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When glucose is heated for a long time with excess HI, what is the final organic product obtained?

1. 1-Hexene
2. Hexanoic acid
3. 6-Iodohexanal
4. n-Hexane

Correct answer: n-Hexane

Solution

Glucose (an aldohexose) undergoes complete deoxygenation when heated with excess HI for a long time. First, the aldehyde and hydroxyl groups react with HI to replace -OH with -I, then the C-I bonds are further reduced to C-H by the HI/red P system, yielding the fully reduced hexane skeleton.

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