Synthetic routes map out synthetic pathways

Chemists create complex compounds, which are often used in medicines or agricultural chemicals.

Typically, synthesising the target compound directly from a single starting material in one step is not feasible.

A synthetic route outlines the sequence of reactions needed to transform starting materials into the desired end product.

It details:

• Every chemical intermediate formed along the way.
• The specific reagents and conditions required at each stage of the process.

For instance, converting 2-chloropropane to propanone isn't a straightforward, one-step process.

Instead, a two-step synthetic route is necessary:

1. 2-chloropropane reacts with KOH, producing propan-2-ol.
2. Propan-2-ol, when treated with acidified K₂Cr₂O₇, yields propanone.

Functional groups dictate reactivity

The behaviour and properties of functional groups significantly affect molecular reactions.

For example:

• Nucleophiles are attracted to the partially positive carbon in halogenoalkanes, but they don't target the electron-rich C=C double bond in alkenes.
• Alcohols, due to their polar O-H bond and the lone pair of electrons on the oxygen atom, can act as nucleophiles.

The following table outlines common reactions associated with key functional groups:

Accurately predicting the reactivity of compounds with multiple functional groups requires identifying each group.

Summary of key organic reactions

Below is an overview of the primary types of organic reactions we've discussed: