Table 1.

Optimization and Control Studies

Entry	Deviation from Standard Conditions	Yield (%)	ir (3a:3b)
1	none	64	1:1.4
2	60 °C	65	1:4
3	60 °C, 0.1 M	67	1:10
4	added LiCl (62.5 mol%)	52	1:1
5	0% FeCl3	0	-
6	in the dark	0	-
7	irradiate at 390 nm 1 h, then dark	2	n.d.
8	427 nm LED	3	n.d.
9	under air	47	1:1

^aReactions were performed on a 0.3 mmol scale. Yields were determined by ¹H NMR using 1,3,5-trimethoxybenzene as the internal standard. n.d.: not determined.