... J. Heterocyclic Chem., 25, 1167 (1988 ... Chemical shifts, expressed in parts per million with respect to TMS, are indicated in Table 1 for the selective data and in the ... b 110.84 (d, C3,), 117.69 (dd, C3.), 123.65 (s, C4g, 125.9 (2 dd, C5, C6.), 134.35 (dd, Cr), 155.70 (s, C„J, 176.94 (s ...