• The first step of the reaction forms the reagent needed for the second half.
• The reagent is formed by way of a nucleophilic attack and an E2 reaction.
• In the interactive example, this reagent is substituted with two Methyl groups. Were these Hydrogen instead, the reagent would be Eschenmoser's salt, CH₂=NH₂⁺.
• This reaction is very useful as the same scheme can be used to form three types of heterocycle.
• Other reactions involving sulphur reactivity: Kornblum, Paal-Knorr Thiophene Synthesis, Pummerer, Ramburg-Backlund and Swern reactions.


References:

• Davis F.A.; Chao B.; Rao A.; Org. Lett., 2001, Volume 3, Issue20, 3169-3171
• Russowsky D.; Petersen R.Z.; Tetrahedron Lett., 2000, Volume 41, Issue 51, 9939-9942