Reaction Steps
A solution of hydroxyacid 81 (1.02 g, 3.86 mmol, 1.00 equiv) and triethylamine (519 μL, 17.37 mmol, 4.50 equiv) in CH2Cl2 (77 mL) was added via syringe pump over 4 h to a solution of 2,4,6-trichlorobenzoyl chloride (904 μL, 5.79 mmol, 1.50 equiv) and N,N-dimethylaminopyridine (DMAP) (519 mg, 4.25 mmol, 1.10 equiv) in CH2Cl2 (39 mL). The solution was then allowed to stir for 30 minutes after complete addition after which it was quenched with H2O (100 mL). The phases were separated and the aqueous phase was extracted with CH2Cl2 (2×100 mL). The organic phases were combined, dried over MgSO4, and the solvent was removed via rotary evaporation to yield a black oil which was purified by silica gel column chromatography (CH2Cl2) to yield 82 (639 mg, 67%) as a yellow oil. Rf=0.52 (CH2Cl2); 1H NMR (500 MHz, CDCl3) δ 7.38 (m, 5H, aryl H), 5.76 (m, 1H, vinyl H), 5.26 (s, 2H, PhCH2), 5.22 (m, 2H, vinyl H), 3.65 (d, 1H, J=16.5 Hz, C(O)CH2), 3.42 (d, 1H, J=16.5 Hz, C(O)CH2), 2.89 (dd, 1H, J=14.6, 6.8 Hz, CHCH2), 2.80 (dd, 1H, J=14.6, 6.8 Hz, CHCH2); 13C NMR (125 MHz, CDCl3) δ 169.03, 165.61, 134.75, 129.10, 128.95, 128.89, 128.59, 121.82, 75.65, 68.17, 45.86, 39.06; IR (neat film) 3034 (w), 1843 (s), 1741 (s), 1644 (w), 1456 (m) cm−1; LRMS (ESI) calcd. for C14H14O4Na (M+Na+) 269.1, observed 269.1.
