| 摘要 |
A process for the preparation of a the formula (I): which process comprises the intramolecular cyclopropanation of an epoxide of me formula (II); in the presence of 0.05 to 0.75 equivalents of a secondary amine base and at least one equivalent of an alkyl lithium base, wherein R R1, R2 and R3 are each hydrogen or C1-4 alkyl or R1 and R2 are linked to form- a C3-7 cycloaUcyl or C3-7 cycloalkenyl ring.
|
