Question

Show how you would accomplish the following conversions in good yields. You may use any necessary reagents.

Short answer

A reagent used is witting reagent$\stackrel{+-}{{\mathrm{Ph}}_3\mathrm{P}-{\mathrm{CHCH}}_3}$

Step-by-step solution

Reagent

A reagent is a substance that is added in the reaction to form the product from the reaction means they are used to complete the chemical reactions.

Witting reaction

It is a reaction that occurs with the aldehyde or ketone to form alkene in the presence of the triphenylphosphonium ylide called witting reagent and also produces phosphonium oxide as a side product.

Reagent used in the reaction

The compound where two adjacent atoms have opposite charge and complete octet are ylides and when ylide reacts with the aldehyde or ketone to form betaine intermediate followed by a 2+2 cycloaddition reaction alkene formation occur.

The geometry of alkene depends upon the reactivity of ylide if the ylide is stabilized the alkene is E and if the ylide is not stabilized alkene is Z.

Formation of product

The reaction between the reactant molecule and the witting reagent results in a formation of the alkene and a phosphene oxide

The reaction followed as:

Witting reaction