... The Journal of Organic ... The organic solution was azeotropically concentrated and filtered through a pad of Solka Floc (filter agent) to provide 4 (1.37 g, 81% HPLC assay) as ... δ 4.38 (s, 2H), 3.63 (m, 1H), 3.27 (m, 2H), 2.17 (m, 1H), 2.02 (m, 2H), 1.62 (m, 1H), 1.37 (d, 3H, J = 6.6 Hz ...