| 摘要 |
<p>The invention comprises compounds of formula <FORM:1101113/C2/1> wherein R is hydrogen, methyl, fluorine or chlorine and R1 is hydrogen or methyl, provided that one of R and R1 is methyl, =CZZ is a group of one of the formulae <FORM:1101113/C2/2> <FORM:1101113/C2/3> <FORM:1101113/C2/4> wherein R2 is hydrogen, hydroxy or C2- 10 aliphatic acyloxy and R5 is hydrogen or acyl, R3 is hydrogen, oxo or b -hydroxy, X is hydrogen or fluorine, and the bonds between the 4,5 and 6,7 positions are both single or both double, or the 4,5 bond is double and the 6,7 bond single and their preparation by treatment with alkali of a compound of formula <FORM:1101113/C2/5></p> |
