Treatment of 2, 4, 6-tri-tert-butylphenol with bromine in cold acetic acid gives the compound C18H29BrO in quantitative

Question:

Treatment of 2, 4, 6-tri-tert-butylphenol with bromine in cold acetic acid gives the compound C18H29BrO in quantitative yield. The infrared spectrum of this compound contains absorptions at 1630 and 1655 cm-1. Its 1H NMR spectrum shows only three peaks (all singlets), at δ 1.2, 1.3, and 6.9 ppm, in the ratio 9:18:2. What is a reasonable structure for the compound?