What carbonyl compound and what phosphonium ylide are required for the synthesis of the following alkene?
There is a six-vertex ring with a CHCH2CH3 group double-bonded by its first carbon to the first vertex.
There are three schemes of reactions. In the first scheme, CH3CCH3 with an O atom double-bonded to the second (from left to right) carbon reacts with a six-vertex ring, which has a P left parenthesis C6H5 right parenthesis 3 group double-bonded to the first vertex. In the second scheme, CH3CH2CH with an O atom double-bonded to the third carbon reacts with a six-vertex ring, which has a P left parenthesis C6H5 right parenthesis 3 group double-bonded to the first vertex. In the third scheme, a six-vertex ring with an O atom double-bonded to the first vertex reacts with CH3CH2CH, which has a P left parenthesis C6H5 right parenthesis 3 group double-bonded to the third (from left to right) carbon.
I
II
III
II or III
I, II, or III