Reaction Steps
To a solution of acid 75 (175.2 mg, 0.599 mmol, 1.00 equiv) in 7:2 PhH:MeOH (6.0 mL) was added a 2.0 M solution of TMSCHN2 (449 μL, 0.899 mmol, 1.50 equiv.). After the resulting gas evolution had subsided, the solvent was removed by rotary evaporation to yield methyl ester 77 (183.7 mg, 100%) as a clear, colorless oil. Rf=0.55 (2:1 hex:EtOAc); 1H NMR (500 MHz, CDCl3) δ 7.36 (m, 5H, aryl H), 5.23 (d, 1H, J=12.1 Hz, PhCH2), 5.19 (d, 1H, J=12.1 Hz, PhCH2), 5.08 (m, 1H, vinyl H), 3.68 (s, 1H, OH), 3.62 (s, 3H, OCH3), 2.95 (d, 1H, J=16.2 Hz, C(O)CH2), 2.72 (d, 1H, J=16.3 Hz, C(O)CH2), 2.41 (m, 2H, CHCH2), 1.67 (s, 3H, C(CH3)2), 1.54 (s, 3H, C(CH3)2); 13C NMR (125 MHz, CDCl3) δ 174.84, 171.43, 136.54, 135.46, 128.70, 128.66, 128.60, 116.75, 75.65, 67.79, 51.93, 42.81, 38.11, 26.06, 18.09; IR (neat film) 3514 (m), 3034 (w), 2955 (m), 1742 (s), 1498 (w), 1439 (s), 753 (m), 699 (m) cm−1; LRMS (ESI) calc'd for C17H22O5Na (M+Na+) 329.2, found 329.1.
