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To a solution of 26 (4.64 g 11.2 mmol) in CH3CN (300 mL) was added water (10 mL) and HgCl2 (15.26 g, 56.21 mmol). After stirring overnight at rt, the mixture was concentrated and partitioned between water (100 mL) and hexane (200 mL). The organic layer was isolated and the aqueous layer extracted with hexane (50 mL). The combined organic extracts were washed with saturated aqueous NaCl and dried over Na2SO4. Concentration to dryness in vacuo at rt gave crude ketone 33 as a yellow oil (3.2 g, 88%): Rf=0.80 (1/9 EtOAc:hexane); 1H NMR (300 MHz, CDCl3) δ 7.58 (d, J=6.4 Hz, 4H), 7.44 (m, 6H), 5.88 (m, 1H), 4.99 (dd, J=17.1, 1.6 Hz, 1H), 4.91 (dd, J=10.2, 1.6 Hz, 1H), 2.50 (d, J=6.6 Hz, 2H), 2.14 (m, 2H), 1.36 (m, 2H), 0.95 (m, 1H), 0.76 (d, J=6.7 Hz, 6H); IR (neat) 3068 (m), 3046(m), 2956(s), 2925 (m), 2864 (m), 1956 (w), 1886 (w), 1826(w), 1641 (s), 1471 (m), 1431 (s), 1113 (s), 1000 (m), 910 (m), 743 (s), 702 (s) cm−1; MS (FAB) m/e (rel. intensity) 323 (MH+, 15), 322 (24), 321 (89), 267, (17), 236 (36), 198 (20), 182 (63), 169 (100), 167 (15), 159 (31); HRMS (FAB) calcd for C23H25OSi: 321.1675 (MH+-2), found: 321.1670.