Barton Decarboxylation via Thiohydroxamate Ester

Summary:

AIBN has been used as a radical initiator in a decarboxylation first developed by Barton. This offers a method to convert it to an alkane. This is a great way to remove one carbon unit if you have too many carbons.The carboxylic acid is transformed into the thiohydroxamate that when exposed to AIBN, tributyl tin hydride and heat allows aromatisation to give a pyridine by-product, the loss of CO₂ and the formation of a radical alkyl group that then obtains a hydrogen from another tributyl tin hydride, to give an alkane and a further tributyl tin radical ready for the next reaction.

Key Words:

AIBN, Tributyl tin hydride, Decarboxylation, Barton, Thiohydroxamate