JPH0227994B

A process for the preparation of 15-hydroxyimino-E-homoeburnane derivatives of the formula (I), (I) wherein X1 stands for hydrogen or halogen and R is a C1-6 alkyl group, or acid addition salts and optically active derivatives thereof. These compounds are valuable intermediates of the synthesis of compounds with outstanding biological effects. According to the invention a racemic or optically active 15-hydroxy-E-homoeburnane derivative of the formula (II), (II) is treated, optionally after separating the 15-epimers and/or resolution, with a halogenating agent. The resulting 15-halo-E-homoeburnane derivative of the formula (III), (III) wherein X2 stands for halogen, is reacted, optionally after separating the 15 epimers and/or resolution, with an alkali nitrite in the presence of an acid, and, if desired, the resulting 15-hydroxyimino-E-homoeburnane derivative of the formula (I) is converted into its acid addition salt and/or resolved. The compounds of the formula (III) formed as intermediates in the above process are new and biologically active.