Cl([O-])(=O)(=O)=O.[Li+].[CH3:7][Mg]Br.[CH3:10][C:11]1([CH3:23])[C:20]2[C:15](=[CH:16][CH:17]=[C:18]([Br:21])[CH:19]=2)[S:14]C(=O)[CH2:12]1.OS(O)(=O)=O.CC[O:31][CH2:32][CH3:33]>>[Br:21][C:18]1[CH:17]=[CH:16][C:15]([SH:14])=[C:20]([C:11]([CH3:12])([CH3:23])[CH2:10][C:32]([CH3:33])([OH:31])[CH3:7])[CH:19]=1To 3.49 g (32.8 mmol) of lithium perchlorate was added under argon 35 ml of 3.0M (105 mmol) methyl magnesium bromide in ether. The above mixture was treated dropwise with stirring with a solution of 2.961 g (10.926 mmol) of 4,4-dimethyl-6-bromo-2-oxo-thiochroman (Compound 31) and the reaction mixture was then heated at reflux for 70 h. The reaction mixture was then allowed to cool and poured onto a mixture of 100 g of ice and 8 ml of conc. H2SO4. The organic layer was separated and the aqueous layer was extracted with 2×25 ml of ether. The organic layers were combined and washed successively with 2×25 ml of saturated NaHCO3 solution, 25 ml of water and 25 ml of saturated NaCl solution and then dried (MgSO4). The solvent was removed in-vacuo and the residue purified by flash chromatography to give the title compound as a pale yellow oil. PHR (CDCl3): & 1.05 (6H, s), 1.52 (6H, s), 2.30 (2H, s), 3.71 (1H, s), 7.22 (1H, dd, J-8.5 Hz, 2.1 Hz), 7.28 (1H, d, J-8.5 Hz), 7.35 (1H, d, J-2.1 Hz)
불러오는 중…
