[S:1]1[CH2:6][CH2:5][CH2:4][S:3][CH2:2]1.C([Li])CCC.[Br:12][C:13]1[CH:14]=[C:15]2[C:19](=[CH:20][CH:21]=1)[C:18](=[O:22])[CH2:17][CH2:16]2.Cl>O1CCCC1>[Br:12][C:13]1[CH:14]=[C:15]2[C:19](=[CH:20][CH:21]=1)[C:18]([CH:2]1[S:3][CH2:4][CH2:5][CH2:6][S:1]1)([OH:22])[CH2:17][CH2:16]2A solution of 1,3-dithiane (11.96 g, 99 mmol) in anhydrous tetrahydrofuran (100 mL) at −30° C. was treated dropwise over 10 min with n-butyllithium (2.5M in hexanes, 38.4 mL, 96 mmol) followed by stirring at −15° C. for 2 h. The solution was then treated with a solution of 5-bromo-2,3-dihydro-1H-inden-1-one (15 g, 71.1 mmol) in anhydrous tetrahydrofuran (250 mL) over 1 h, maintaining the temperature between −9° C. and 2° C. The mixture was then allowed to set in the refrigerator at 2-8° C. for 18 h. The solution was concentrated in vacuo to afford a maroon oil, which was treated with 1 N hydrochloric acid solution and extracted with ether. The ether layer was extracted with saturated sodium chloride solution, dried (Na2SO4) and concentrated in vacuo to afford an amber oil (23.55 g).
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