Chapter 12, Problem 67IP

Interpretation Introduction

Interpretation:

A synthesis of estragole starting from 4- methyl phenol possible route has to be proposed.

Concept Introduction:

Methylation: phenol reaction with methyl bromide in the presence of base like sodium hydroxide gives methoxy product.

NBS: N-Bromo succinimide is the brominating agent and it is used as a source of bromine in radical reaction.

The Grignard reaction:

Alkyl, vinyl, or aryl-magnesium halides ($\text{RMgX}$) is called as Grignard reagent. Grignard reagent is reaction with carbonyl compound such as aldehyde or ketone, produces corresponding alcohol is the product and it is the one of the carbon – carbon bond forming reaction.

    

Tosylation reaction:

The alcohol is treated with any tosyl chloride (methane sulfonyl chloride) which yields tosylated product this reaction is called as alkyl tosylate and which is shown below,

Elimination reaction: An elimination reaction is removal of two substituents in a molecule and forms alkene.

Lindlar reduction: The alkenes or alkynes can be reduced to alkanes with ${\text{H}}_{\text{2}}$ in the presence of metal catalyst $\left(\text{Pd}\right)$. This heterogeneous catalyst that consists of palladium deposited on calcium carbonate which is then poisoned with various forms of lead or Sulphur.  The new $\text{C-H σ}$ bonds are formed simultaneously from $\text{H}$ atoms absorbed into the metal surface. Potassium tert-butoxide is a strong base, which used for the abstraction of acidic hydrogen from the molecule.