Chapter 21, Problem 21.11P

Interpretation Introduction

(a)

Interpretation: The reagent required to convert the given compound into butanal is to be predicted.

Concept introduction: Diisobutylaluminiumhydride(DIBAL-H) is a selective reducing agent. It readily converts esters into aldehydes.

Interpretation Introduction

(b)

Interpretation: The reagent required to convert the given compound into butanal is to be predicted.

Concept introduction: The full form of PCC is pyridinium chlorochromate. It acts as mild oxidizing agent. It oxidizes primary alcohols into aldehyde and secondary alcohol into ketones.

Interpretation Introduction

(c)

Interpretation: The reagent required to convert the given compound into butanal is to be predicted.

Concept introduction: A stepwise procedure of transforming an alkyne into a carbonyl group is known hydroboration-oxidation reaction. In a hydroboration-oxidation reaction, an alkyne reacts with ${\text{BH}}_{\text{3}}$ followed by ${\text{H}}_{\text{2}}{\text{O}}_{\text{2}};{\text{OH}}^{-}$ to form an aldehyde.

Interpretation Introduction

(d)

Interpretation: The reagent required to convert the given compound into butanal is to be predicted.

Concept introduction: In presence of ozone and $\text{Zn},{\text{H}}_{\text{2}}\text{O}$, oxidative cleavage occurs. In oxidative cleavage both the sigma and pi bond of the alkene is broken and two carbonyl compounds are formed. Depending upon the alkyl substituents, aldehyde or ketone is formed.