The general procedure for the synthesis of tert-butyl 1-amino-3,6,9,12-tetraoxapentadecan-15-oate from 1-(p-toluenesulfonyloxy)-3,6,9,12-tetraoxapentadecan-15-oate is as follows: 150 g of the sulfonated crude product was dissolved in 200 mL of methylene chloride, followed by the addition of 100 g of ammonium hydroxide and 10 g of tetrabutyl ammonium bromide. The reaction mixture was warmed to 40 °C with continuous stirring for 24 hours. Upon completion of the reaction, the solvent was removed by rotary evaporation. To the residue, 3 M hydrochloric acid solution was added and the pH was adjusted to 3. The organic phase was separated by extracting twice with 300 mL of dichloromethane. The pH of the aqueous phase was then adjusted to 9 with sodium hydroxide solution and extracted three times with 400 mL of dichloromethane. The organic phases were combined, dried with anhydrous sodium sulfate, filtered and the solvent was removed by rotary evaporation to give 50 g of aminocapped product. The structure of the product was confirmed by NMR.
