CN(C)[CH2:3][CH2:4]N(C)C.[Li]C(CC)C.[C:14]([C:18]1[CH:26]=C[C:21]([C:22]([OH:24])=[O:23])=[CH:20][CH:19]=1)([CH3:17])([CH3:16])[CH3:15].CI>C1COCC1>[C:14]([C:18]1[CH:19]=[CH:20][C:21]([C:22]([OH:24])=[O:23])=[C:3]([CH3:4])[CH:26]=1)([CH3:17])([CH3:15])[CH3:16]A 250 mL round bottom flask was charged with tetramethylethylene diamine (5.6 mL, 37 mmol) in THF (34 mL). After the mixture was cooled to −92° C. (N2(liq)/CH2Cl2 bath), sec-BuLi (26.5 mL, 37 mmol, 1.4M solution in cyclohexane) was added, followed by the dropwise addition of a solution of 4-tert-butylbenzoic acid (3 g, 16.8 mmol) dissolved in THF (22 mL). After stirring for 1 h, methyliodide (4.5 mL, 72.4 mmol) was added to mixture at −80° C. After stirring for 10 min at −80° C., the reaction mixture was quenched H2O (20 mL). Upon warming to room temperature, the aqueous phase adjusted to pH=2 with aqueous HCl (1M). The aqueous phase was extracted with EtOAc (2×15 mL), and the combined organic extracts were dried with Na2SO4 and concentrated. The residue was chromatographed with (gradient, 10%-60% EtOAc/hexanes) to afford 630 mg (20%) 101a.
불러오는 중…
