This is an example of a reaction involving thionyl chloride. The alcohol is halogenated with excess thionyl chloride to yield chloro lactone. The paper is a study on the biomimetic (mimicking a biological process) synthesis of bisesquiterpene lactones, specifically biatractylolide and biepiasterolide which have been extracted from Atractylodes macrocephala (Chinese medicinal plant).

This is one of the synthesis steps to produce tolterodine tartrate. The focus of the study was to find a cost-effective and impurity-free process to produce tolterodine tartrate. This compound is a muscle relaxant used to treat bladder disorders. Although ethers are inert to most reagents, a benzyl ether, like the one above, can be hydrogenated under mild conditions (H2/Raney/Ni/MeOH/25-30 C) to an alcohol. The phenyl group stays and the methylbenzene group leaves.

Organic molecules contain carbon

Alcohol
hydrocarbon with a hydrogen replaced by “OH”.
Acid
hydrocarbon with a hydrogen replaced by a carboxyl “COOH”.
COOH -> COO- + H+
Amine
hydrocarbon with a hydrogen replaced by an amine “NH2″. Basic- accepts protons. NH2 + H+ -> NH3+
Phosphate
addition of -PO4= (switch)
Amino Acid
hydrocarbon with amino and carboxyl groups