Table 6. Comparison of SMA's catalytic efficiency for the synthesis of 2g with that of other catalytic systems.

Catalyst	Amount of catalyst	Yield (%)	Solvent	Time (min)	Temperature (°C)
Yb(PFO)3 (ref. 51)	5 mol%	90	EtOH	300	60
TBAF52	10 mol%	97	Water	30	Reflux
Re(PFO)3 (ref. 53)	5 mol%	90	EtOH	300	60
Yb(OTf)3 (ref. 54)	5 mol%	78	EtOH	300	60
Nano-TiO2–SO3H29	0.2 mol%	90	—	30	80
SMA (this work)	1 mol%	93	EtOH	15	rt