Reaction Steps
To a mixture of Ethyl 2-pentynoate (5.5 g, 43.6 mmol), 1-iodo-4-(methoxymethoxy)benzene (23.0 g, 87.1 mmol), Phenylboronic acid (10.6 g, 86.9 mmol) in DMF (132 ml) was added a solution of K2CO3 (12.1 g, 87.5 mmol) in H2O (33 ml) under ice cooling, then the mixture was stirred at room temperature for 10 min. PdCl2(PhCN)2 (167 mg, 0.435 mmol) was added under Ar atmosphere, and the mixture was stirred at room temperature for 24 h. The reaction was quenched with H2O under ice cooling, and the whole was extracted with Et2O. The organic layer was washed with H2O, brine, dried over Na2SO4, then concentrated. Purification by silica gel flash column chromatography (eluent: hexane/AcOEt, 30:1 to 10:1) gave 2 (29%) and the regioisomer (24%). 2: colorless oil; 1H-NMR (CDCl3) δ 1.00 (3H, t, J=7.4), 1.31 (3H, t, J=7.1 Hz), 2.63 (2H, q, J=7.4 Hz), 3.42 (3H, s), 4.28 (2H, q, J=7.1 Hz), 5.07 (2H, s), 6.75 (2H, d, J=8.8 Hz), 6.90 (2H, d, J=8.8 Hz), 7.04 (2H, m), 7.12-7.21 (3H, m); regioisomer: H1-NMR (CDCl3) δ 1.02 (3H, t, J=7.4 Hz), 1.29 (3H, t, J=7.1 Hz), 2.64 (2H, q, J=7.4 Hz), 3.45 (3H, s), 4.27 (2H, q, J=7.1 Hz), 5.10 (2H, s), 6.81 (2H, d, J=8.8 Hz), 6.95 (2H, d, J=8.8 Hz), 7.00 (2H, m), 7.06-7.14 (3H, m).
