Clean, one-pot synthesis of 4H-pyran derivatives catalyzed by hexadecyltrimethyl ammonium bromide in aqueous media

An efficient and convenient synthetic route to 4H-pyran derivatives in water in the presence of hexadecyltrimethyl ammonium bromide (HTMAB) as catalyst is described. This method provides several advantages such as environment friendliness, high yields, and a simple workup procedure. In addition, water was chosen as a green solvent.