There is provided a process for the preparation of an enantiomer of a compound of formula (I) which process comprises separation thereof from a mixture of diastereoisomers of a compound of the formula (I):
wherein R is acetyl, a-hydroxyethyl or a protected derivative thereof, and R' and R2 are substituted or unsubstituted hydrocarbon groups, or are joined so as to form a carbocyclic or heterocyclic ring; at least one of R' and R2 containing a chiral centre, such that the enantiomer can be separated thereby; and R3 and R4 are independently hydrogen or an organic group bonded via a carbon atom to the tetrahydro-oxazine ring, or R3 and R4 are joined so as to form together with the carbon atom to which they are attached an optionally substituted C3-7 cycloalkyl or optionally substituted heterocyclyl ring.
The enantiomer is of use in the preparation of optically active carbapenem antibiotics.
提供了一种制备式(I)化合物对映体的工艺,该工艺包括从式(I)化合物的非对映异构体混合物中分离出对映体:
其中 R 是乙酰基、a-羟乙基或其保护衍
生物,R'和 R2 是取代或未取代的烃基,或连接形成碳环或杂环;R'和 R2 中至少有一个含有手性中心,从而可分离出对映体;R3 和 R4 独立地为氢或通过一个碳原子与四氢恶嗪环键合的有机基团,或 R3 和 R4 键合后与所连接的碳原子一起形成任选取代的 C3-7 环烷基或任选取代的杂环烷基。
对映体可用于制备光学活性碳青霉烯类抗生素。