Synthesis of Isoxazolopyridines and Spirooxindoles under Ultrasonic Irradiation and Evaluation of Their Antioxidant Activity

Table 3

Synthesis of spirooxindole derivatives in the presence of catalytic amount of (±)-CSA.

Entry	-Diketone	Product	Time (min)	Yield
a			30	80 [22]
b			30	88
c			30	90
d			30	76

yield.