Question

A Wittig reaction with an aldehyde gives:
(A) Ketone
(B) A long chain fatty acid
(C) Olefin compound
(D) Epoxide

Answer 1

Olefins are also known as alkene. This is because alkenes are unsaturated and hence leads to the formation of oil based compounds. We use the ylide as the reagent in the Wittig reaction.

Complete step by step solution:
Wittig reaction is an organic reaction. An aldehyde or ketone reacts with the wittig reagent which is known as triphenyl phosphonium ylide to yield alkene and triphenylphosphine oxide. This is a very common method for the synthesis of the alkenes. One of the major advantages of this reaction is that the position of double can be determined accurately depending upon the type of aldehyde. This is not so in the formation of alkene through dehydration of alcohol which creates a mixture of alkene with different positions of double bonds. The advantages of Wittig reactions are that alkene can be synthesized from either ketone or aldehyde.
The ylide group is also compatible with other carbonyl groups such as acid and esters. The structure of the final product will depend on the nature of ylide used. The disadvantage of this reaction includes the formation of both the optically active isomers that are E and Z. When we use bulky ketone they cause steric hindrance which reduces the rate of reaction and makes it kinetically slower. Aldehyde may also undergo decomposition during the reaction.
Thus, the correct option is C.

Note:
This reaction was found out by the scientist named Georg Wittig, he was a german scientist and was also awarded with the Nobel Prize for the discovery of this reaction.