Preparation of 4,7,13,16,21-pentaoxa-1,10-diazabicyclo[8.8.5]tristeethane: In an argon-flushed flask having a Friedrichs condenser, 225 grams of commercially available trioxane (225 grams) was mixed with 10 grams of KOH and 10 grams of polyethylene glycol (molecular weight = 600). The mixture was refluxed with stirring for 4 hours and then 197.0 g was distilled into a dry, argon-flushed resin kettle. The distilled trioxane was melted at 70 C and mixed with 6.6 ml (2.98 wt%) of ethylene oxide. The reaction was initiated with 3.5 ml of 0.03113MBF3.OEt2 in dichloromethane solution and after 54 min it had polymerized to solid 4,7,13,16,21-pentaoxa-1,10-diazabicyclo[8.8.5]eicosane.