Sulfite ester

A sulfite ester (also known as an organosulfite) is a functional group with the structure (RO)(R'O)SO.

They adopt a trigonal pyramidal molecular geometry due to the presence of lone pairs on the sulphur atom.

[1] The reaction is typically performed at room temperature to prevent the alcohol being converted into a chloroalkane.

Bases such as pyridine can also be used to promote the reaction: The pesticides endosulfan and propargite are sulfite esters.

[2] Mono-esters, with the general structure (RO)(HO)S=O are a rare subclass.