Table 2.

Scope of the Fluoro-Prins Reaction^a

entry	R	3	yield (%)	cis-3/trans-3b
1	C6H5–	3a	75	17:1
2	2-naphtyl	3b	74	>20:1
3	4-ClC6H4–	3c	87	>20:1
4	4-BrC6H4–	3d	91	>20:1
5	4-NO2C6H4–	3e	81	>20:1
6	4-CF3C6H4–	3f	92	>20:1
7	4-i-PrC6H4–	3g	78	>20:1
8	4-MeC6H4–	3h	72	>20:1
9	2-NO2C6H4–	3i	76	>20:1
10	4-OH-3,5-dimethoxy-C6H2	3j	ro rxn
11	6-Br-2-OH-3-MeO-C6H2	3k	56	> 20:1
12	cyclohexyl–	3l	88	20:1

^a1 (0.2 mmol), 2 (0.2 mmol), and DMPU/HF (2.1 mmol HF) in DCM (0.5 mL) was mixed in a plastic vial and then stirred for 3 h at rt.

^bDetermined by ¹⁹F NMR.