Major and minor products

What exactly is a major and minor product?

This question is from two sets of reactions between prop-1-ene and hydrogen bromide. Both have products of (i don't know the name) it is a ethane molecule with a methyl and Br group on carbon atom 1 (2, bromo propane?). Both the reaction says that that product is a major in one and a minor on the other. So what is this major/minor product?

Reply 1

Zoob

Read about unsymmetrical alkenes here

Reply 2

Eau

A major product is one that is produced more in a given reaction because it is favoured. Minor product less.

Now when HBr reacts with propene, two intermediates - carbocations- can be formed. One where the positive carbon is stabalised by the "donating" methyl group, one that is not. The intermediate that is stabalised by the methyl group will be favoured.

Hence the major product in this reaction would be 2-bromopropane. Minor product will be 1-bromopropane.