[C:1]([C:5]1[CH:10]=[C:9]([C:11]([CH3:14])([CH3:13])[CH3:12])[CH:8]=[CH:7][C:6]=1[O:15][CH2:16][CH:17]([F:19])[F:18])([CH3:4])([CH3:3])[CH3:2].[I:20]N1C(=O)CCC1=O.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>ClCCl>[C:1]([C:5]1[CH:10]=[C:9]([C:11]([CH3:12])([CH3:13])[CH3:14])[CH:8]=[C:7]([I:20])[C:6]=1[O:15][CH2:16][CH:17]([F:18])[F:19])([CH3:2])([CH3:3])[CH3:4]2,4-Di-tert-butyl-1-(2,2-difluoro-ethoxy)-benzene (6.75 g, 25 mmol), N-iodosuccinimide (6.74 g, 30 mmol) and p-toluenesulfonic acid monohydrate (1.90 g, 10 mmol) were combined in dichloromethane (75 mL) and heated at 38° C. for 7 h. TLC (hexanes) indicated a small amount of starting material still present and the reaction was treated with additional N-iodosuccinimde (0.33 g). After 4 h the reaction was washed with 10% Na2SO2O3 solution (50 mL). The aqueous was backwashed with dichloromethane (100 mL) and then the combined organic portions washed with water (75 mL) and the combined organic portions washed with water (100 mL), dried (MgSO4), filtered and evaporated in vacuo to provide an orange oil (9.92 g). The material was purified by flash chromatography using hexane to give 8.88 g (90%) of a light pink oil which solidified over time. 1H NMR (250 MHz, CDCl3): δ 7.66 (d, 1H, J=2.4), 7.36 (d, 1H, =2.4), 6.29 (tt, 1H, J=55.3, J=4.3), 4.24 (td, 2H, J=13.2, J=4.3), 1.40 (s, 9H), 1.29 (s, 9H).
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