... Kathlyn A. Parker* and James G. Farmar Department of Chemistry, Brown University, Providence, Rhode Island 02912 Received July 14, 1986 ... H, 19J, 5.58 (m, 0.05 H, 20,), 5.83 (br d, J = 12 Hz, 0.05 H, 20,), 6.14 (d, J = 16 Hz ... The combined organic solution was concentrated. ...