The mother liquor provided a second crop of crystals, and the resulting mother liquor showed a 59:35 E:Z ratio. Partial spectra: *H NMR (270 MHz, CDC13) 5.83 (bs, 0.06 H), 5.62 (bs, 0.59 H), 5.32 (bs, 0.35 H), 1.44 (s), 1.26 (s), 1.11 (s); 13C NMR (67.9 MHz, PhH-d6) 22.5 (q), 21.1 (q), 15.8 (q). Method B from 20. To a stirred solution of acetate 20 (85.1 mg, 0.23 mmol) in 1.1 mL of dry Me2SO (previously deoxygenated by flushing with argon) at 25 °C under argon was cautiously added NaH (5.2 mg, 0.22 mmol). The mixture was stirred for 2 h to give a clear, orangeyellow solution. Catalyst 29 (12.8 mg, 0.014 mmol) was added, and the mixture was heated to 130 °C over 15 min. After 45 min at 130 °C the deep red-brown solution was cooled to 25 °C, concentrated in vacuo, and filtered through Florisil (5 X 0.5 cm) with EtOAc (20 mL). Concentration in vacuo and preparative TLC purification, using three elutions with 20% acetone in hexane (v/v), yielded the same product as above (35.8 mg, 52%) as an off-white solid, the physical and spectral characteristics of which were identical with those of the material obtained from reaction of the enol ether. The progress of the reaction can be followed by analytical TLC or NMR, and it clearly proceeds through the intermediacy of the enol ether 21.