1H NMR (400 MHz, CDCl3) δ 7.75 (d, J = 8.3 Hz, 2H), 7.47 (d, J = 8.3 Hz, 2H), 5.87 (s, 1H), 5.66 (s, 1H), 3.53 (s, 2H), 2.12 (s, 3H), 1.34 (s, 9H); 13C NMR (100 MHz, CDCl3) δ 196.6, 156.3, 143.8, 134.7, 129.6, 125.2, 125.1, 35.5, 35.0, 31.1, 15.4. HRMS (EI): calcd for C15H20OS: 248.1235; found: 248.1231.