... a 16.8-HZ coupling constant for the olefinic hydrogens confirmed the trans stereo- chemistry of 4 ... The com- bined organic extracts were washed with 300 mL of saturated aqueous sodium bicarbonate, dried ... 18.3, 16.8, 1.2 Hz), 4.06 (quintet, J = 7.0 Hz, 4 H), 3.97 (dd, J = 6.7, 1.2 ...