Chapter 11, Problem 39IP

Interpretation Introduction

Interpretation: The root of the Asian plant known as kakkon has long been utilised in Chinese medicine. It has a fruity, vinous, and medicinal scent. Some chemicals, notably 2,5-hexanedione, were identified because of research on the volatile kakkon constituents (those responsible for the aroma). A synthesis of this diketone, starting from $3,4-\text{dimethylcyclobutene}$_, is to be proposed.

Concept introduction:

The product contains two ketone groups, which is suggestive of ozonolysis.

$\text{HBr}$ converts symmetric alkenes into alkyl halides. However, $\text{HBr}$ converts asymmetric alkenes into alkyl halide by Markovnikov addition. According to Markovnikov's rule, the negative half of an asymmetrical reagent will connect to the carbon atom that has fewer hydrogen atoms when it is introduced to an unsymmetrical alkene.