Comparison of the present approach with literature reported method for 4H-pyrans synthesis.

Entry	Catalyst (mol%)	Solvent	Time (min)	Temp. (°C)	Yield (%)	Ref.
1	KF–Al2O3	EtOH	180	r.t	77	64
2	Fe3O4@gC3N4	EtOH	190	60	80	65
3	Piperazine	H2O	7	90	96	66
4	Fe3O4@GA@isinglass	EtOH	50	Reflux	88	51
5	[2-aemim][PF6]	M.W	3	100	87	67
6	Fe 3 O 4 @NFC@Co( ii )	H 2 O	15 min	50	98	This work