摘要 |
A compound of formula (I)
wherein
n is 0 to 4;
R is ethyl or vinyl;
R 1 is hydrogen or (C 1-6 )alkyl,
R 2 is hydrogen or
- cycloalkyl including (C 3-6 )cycloalkyl, or
- unsubstituted (C 1-6 )alkyl, or
- (C 1-6 )alkyl substituted by one or more of
- hydroxy; preferably one or two,
- halogen,
- (C 3-6 )cycloalkyl, or
R 1 is hydroxy and R 2 is formyl. |