Which product results from the Wittig reaction of benzaldehyde with methylidenetriphenylphosphorane?

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Multiple Choice

Which product results from the Wittig reaction of benzaldehyde with methylidenetriphenylphosphorane?

Wittig reactions create alkenes by coupling a carbonyl compound with a phosphorane ylide. When the ylide is methylidenetriphenylphosphorane (Ph3P=CH2), it donates a CH2 unit to form a carbon–carbon double bond with the carbonyl carbon from the aldehyde. With benzaldehyde, the benzene ring carries the carbonyl carbon, and the CH2 from the ylide becomes the other end of the double bond, yielding PhCH=CH2, which is styrene. The reaction also gives triphenylphosphine oxide as a byproduct. So the product is styrene.

Wittig reactions create alkenes by coupling a carbonyl compound with a phosphorane ylide. When the ylide is methylidenetriphenylphosphorane (Ph3P=CH2), it donates a CH2 unit to form a carbon–carbon double bond with the carbonyl carbon from the aldehyde. With benzaldehyde, the benzene ring carries the carbonyl carbon, and the CH2 from the ylide becomes the other end of the double bond, yielding PhCH=CH2, which is styrene. The reaction also gives triphenylphosphine oxide as a byproduct. So the product is styrene.

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