“…The cross peak (3,13), which shows the 4-bond W-coupling between H-3 and H-13, gives the precise assignment ofH-3 (0 2.09). The remained spin system (CII-C8-C9-CIO) was observed as the cross peaks (11, 11 '), (11,8), (11', 8), (8,9), (9,10), (11', 10'), (11', 9'), (8,14) and (11,14). The signal of H-11', which was strongly deshielded by the carbonyl group at C4 (discussed later), was weakly coupled with H-IO'.…”