Filing Date: 2007-07-27.-- Priority Data: EP 06380219.3 (2006-07-28)The present invention relates to a method for the preparation of derivatives of dimethano-[1,3]dioxocino[6,5-d]pyrimidine-spiro derivatives of formula II, III and IV. The present invention also relates to the derivatives of formula II, III and IV obtained through the method described, to pharmaceutical compositions comprising the same and to their use as a medicament.