What carbonyl compound and what phosphonium ylide are required for the synthesis of the following alkene?
A)I
B)II
C)III
D)II or III
E)I, II, or III

Question

What carbonyl compound and what phosphonium ylide are required for the synthesis of the following alkene?  
A)I 
B)II 
C)III 
D)II or III 
E)I, II, or III

Quizplus · Accepted Answer

The synthesis of the given alkene requires a phosphonium ylide and a carbonyl compound that can form a beta-hydroxy carbonyl intermediate. A beta-hydroxy carbonyl intermediate can be formed by the reaction between an aldehyde or ketone and a phosphonium ylide. Option I is not a suitable carbonyl compound as it lacks the necessary alpha-hydrogens. Option III is not a suitable ylide as it has two bulky groups that would hinder the reaction. Option II is a suitable ylide, but the carbonyl compound is an ester that cannot form a beta-hydroxy carbonyl intermediate. Therefore, the best choice is option D, as both options II and III can be used to synthesize the required alkene.

What Carbonyl Compound and What Phosphonium Ylide Are Required for the Synthesis