Brønsted acid-catalysed desilylative heterocyclisation to form substituted furans.

Heterocyclisation of tert -butyldimethylsilyl (TBS) protected γ-hydroxy-α,β-unsaturated ketones catalysed by para -toluenesulfonic acid ( p -TSA) to form substituted furans is reported. The reaction proceeds under mild conditions at room temperature in methanol to give a range of furan products (21 examples, up to 98% yield). Mechanistic experiments suggest the reaction proceeds via in situ deprotection followed by catalytic dehydrative heterocyclisation.