... In support of this supposition of relative electrophilicity, the 13C chemical shifts of the side chain carbonyl groups of compounds 4–6, indicative of their ... 4.72 (1H, m), 5.17 (2H, d, J = 12.0 Hz), 5.79 (1H, s), 6.83 (1H, s), 7.27–7.37 (7H, m), 8.25 (2H, d, J = 9.1 Hz ... 2007 NRC Canada ...