in this specification is not and should not be taken as an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in australia the invention will now be described with reference to the following examples which are intended only for the purpose of illustrating certain embodiments of the invention and are not to be taken as limiting the generality of the invention previously described formic acid 45 100 l is added to ethanol 100 l oripavine is dissolved in the acidic ethanol 100 kg 200 l 50 hydrogen peroxide 70 l is added and the temperature is maintained at 20 u00b0 c by cooling after 2 hrs the reaction mixture is neutralised to ph 7 with the addition of 23 naoh at a rate which ensures that the temperature of the reaction reaches 55 u00b0 c this is performed over 2 hrs when this temperature is reached the mixture is allowed to react for a further 1 2 hrs after this time the reaction mixture is cooled to 15 u00b0 c and solid material filtered the filtered cake is washed with water 100 l 100 kg and then with ethanol 80 yield lc ms m z 316 m h b reduction of 14 no to oxazolidine compound of formula iv where r u2550 h 14 hydroxymorphinone n oxide 14 no 4 kg is added to 100 l of methanol gt 98 the resultant slurry is stirred for 5 minutes to the slurry is added 0 8 kg feso 4 7h 2 o and the resultant mixture is vigorously stirred for about 5 minutes after 2 minutes 15 l of 85 formic acid is added and.