1022
J . Med. Chem. 1980, 23, 1022-1026
6.05-6.45 (m, 5, C-7, C-8, and C-12 HC=CH, C-10 and C-14 C=CH), 7.01 (dd, J = 15 and 11 Hz, 1,C-11 HC=CH), 13.5 (very broad s, 1,NH); 13C NMR (CDC13)12.9 (C-19), 15.4 (C-20), 19.3 (C-3), 21.7 (C-l8), 29.0 (C-16 and C-17), 33.2 (C-4), 34.3 (C-l), 39.8 (C-2), 109.0 (C-14), 128.7, 129.5, 130.0, and 130.5 (C-5, C-7, C-10, and C - l l ) , 134.7 (C-12), 137.3, 137.8, and 139.5 (C-6, C-8, and C-9), 147.9 and 154.3 ppm (C-13 and C-15); UV, ,A (EtOH) 341 nm (e 5.48 X lo4). MS Calcd for CmH%N4:324.2314. Found: 324.2312. The all-E configuration was assigned by 'H and 13C NMR comparison with the retinoic acid isomers. The proton chemical shifts of H-12 and H-8 (6
