ml water stirred for 5 minutes and the mixture filtered the amorphous solid obtained was discarded and the filtrate allowed to separate the upper layer was then discarded the lower methylene chloride phase washed twice with water dried over anhydrous sodium sulphate and after filtration all solvent was then removed by vacuum distillation 161 g of an amorphous solid was obtained 225 ml of methanol were added to this solid and refluxed for two hours with stirring the reaction mixture was then cooled to about 0 u00b0 c filtered and the solid washed with cold methanol and vacuum dried at 80 u00b0 c 51 g of beta etoposide triacetate essentially free of alpha etoposide triacetate was obtained whose assay was 91 3 beta etoposide triacetate was first prepared using the procedure of example 1 a mixture of 50 g beta etoposide triacetate 50 g zinc acetate dihydrate and 500 ml methanol were refluxed while being stirred for 96 hours the mixture was cooled and the solvent removed by vacuum distillation an amorphous solid residue remained to this residue 300 ml methylene chloride 300 ml water and 30 ml glacial acetic acid were added and the mixture was stirred at ambient temperature 25 u00b0 c until all the solid dissolved the two phases now present were separated and the upper aqueous phase was washed with methylene chloride the combined methylene chloride phases were washed 5 times with 300 ml water 50 ml of methanol was added to the first and third washes to prevent precipitation of etoposide the.