... Elemental analyses were performed by the Microanalytical Laboratory, operated by the College of Chemistry, University of ... The combined organic fractions were dried over MgSO,, and the solvent was removed with a ... 9), 0.93 (s, 9), 2.56 (m, 4), 3.67 (s, 3), 4.52 (quintet, 1, J = 6.1). ...