Table 9.

Effect of irradiation time on the yield of photochemical flavanone 87b formation from 2'-hydroxychalcones.

Solvent	Irradiation time/h	86b (mM Recovered)a	87b (mM Formed)	Yield of 87b (%)b
Benzene	5	0.77	0.17	74
	10	0.66	0.24	71
	15	0.55	0.34	69
	20	0.52	0.40	83
1,4-dioxane	1	0.79	0.17	82
	2	0.57	0.48	100
	3	0.31	0.55	79
	4	0.06	0.35	58
EtOAc	2	0.57	0.45	100
	3	0.32	0.62	91
	4.5	0.23	0.65	84
	6	0.14	0.86	100

^a Initial concentration of 86b was 1 mM; ^bThe yield of 87b was based on the consumed amount of 86b.