were added followed 15 minutes later by 0 5 ml 4 05 u00d7 10 3 mole of diisopropenyl ether the reaction was completed after another hour of stirring and the solvent evaporated under reduced pressure the crude liquid was chilled and filtered to remove 0 32 g 2 75 u00d7 10 3 mole of starting diol vacuum distillation at 21 24 mm hg 2 8 3 2 kpa in the presence of diphenyl ether as a high boiling solvent produced 1 93 g 92 percent product and 7 2 percent diphenyl ether boiling point 84 u00b0 c to 85 u00b0 c and 0 31 g 77 percent product and 22 percent diphenyl ether boiling point 88 u00b0 c to 90 u00b0 c of colorless liquid the yield was 1 29 u00d7 10 2 mole 52 percent the product has a boiling point of 92 u00b0 c to 96 u00b0 c at 22 mm hg 2 9 kpa nuclear magnetic resonance and mass spectrum analysis showed the product to have the structure str10 five microliters 6 5 u00d7 10 5 mole of cf 3 cooh were added to a solution of 7 41 g 4 07 u00d7 10 2 mole of d mannitol and 8 0 ml 6 48 u00d7 10 2 mole of diisopropenyl ether in 50 ml of heated dimethylsulfoxide at a constant temperature of 65 u00b0 c after 70 minutes 1 5 ml 1 22 u00d7 10 2 mole of diisopropenyl ether was added forty seven minutes later the dimethylsulfoxide was evaporated at 18 mm hg 2 4.