[CH3:1][C:2]1([CH3:12])[CH:7]2[CH2:8][CH:3]1[CH2:4][CH:5]=[C:6]2[CH2:9][CH2:10][OH:11].[Li]CCCC.[C:18]1([CH3:28])[CH:23]=[CH:22][C:21]([S:24](Cl)(=[O:26])=[O:25])=[CH:20][CH:19]=1>O1CCCC1.[Hg]>[CH3:1][C:2]1([CH3:12])[CH:7]2[CH2:8][CH:3]1[CH2:4][CH:5]=[C:6]2[CH2:9][CH2:10][OH:11].[S:24]([C:21]1[CH:22]=[CH:23][C:18]([CH3:28])=[CH:19][CH:20]=1)([O-:11])(=[O:26])=[O:25]A dry, 2-L flask equipped with a septum inlet, magnetic stirring bar, and a reflux condenser leading to a mercury bubbler was flushed with dry nitrogen and maintained under static pressure of nitrogen. The flask was charged with 170 mL (1 mol) of (-)-nopol [[α]23D 40.2% (neat)] and 400 mL tetrahydrofuran (THF) and cooled to -78° C.. While the solution was stirring at -78° C., 455 mL (2.2 M, 1 mol) of n-BuLi was added slowly and stirred for 1 h at -78° C.; 190 g (1 mol) of p-toluenesulfonyl chloride in 200 mL of THF was added slowly and the stirring continued for another hour at at -78 C. It was then warmed to room temperature and stirred for 2 h. The reaction mixture was poured into ice-water and extracted with pentane. Evaporation of the solvent gave a thick semi-solid of nopol tosylate in 90% yield (290g). Nopol tosylate (290g) was dissolved in hot pentane (800 mL) and stored at 0° C. for 12 h to insure complete crystallization. Colorless white needles of Nopol tosylate (mp 50°-51° C.) were recovered by fast filtration in 85% yield.
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