Results of the synthesis of 4a–4gvia the irradiation of 2a–2g in HCl/acetal at 419 nm.

En.	Starting	Conv. (%)	Yield (%) based on conversion	Yield of 4 (%)	3-Step yield (%)
1	2a: H	93	96	89.28	81.37
2	2b: Me	76	86	65.36	57.69
3	2c: Et	75	86	64.50	55.68
4	2d: i-Pr	72	73	52.56	45.45
5	2e: F	67	91	60.97	52.09
6	2f: Cl	66	91	60.06	53.56
7	2g: Br	77	90	69.30	63.80