A theoretical conformational study of 1,2,4,5-trioxazine and some alky
l and phenyl derivatives was performed with the semiempirical AMI, PM3
and MNDO/3 techniques as well as with an ab initio method with a limi
ted basis set. A reasonable agreement was found among the different ca
lculation procedures, suggesting a chair conformation for the molecula
r rings of these molecules as the most stable one.