The sulfur-containing esters can be divided into two classes; one in which the sulfur atom belongs
to the organic acid, such as CH3SCH2CH2COOCH3, and the other in which the sulfur atom is from an
alcohol or mercaptan (AOM), such as CH3COOCH2CH2SCH3 or CH3COSCH2CH2CH3. The first
sulfur-containing ester class can be synthesized by the thia-Michael addition reaction, which is facile
and efficient [1-3].