The present invention relates to a halo-lactonization process for the stereoselective preparation of protected 1-(halo-methyl)-3-oxo-2-oxa-5-azabicyclo[2.2.1]heptane derivatives of formula (II)
wherein Hal and R1 are as defined in the description. The invention further relates to the novel compounds of formula (II), and to their further transformation to the compounds of formula (III)
wherein R1, R2, R3, and R4 are as defined in the description.
本发明涉及一种卤代内酯化过程,用于选择性地制备保护的1-(卤代甲基)-3-氧代-2-氧代-5-氮代
双环[2.2.1]庚烷衍
生物的立体选择性,其
化学式为(II),其中Hal和R1如描述中所定义。该发明还涉及
化学式(II)的新化合物,以及它们进一步转化为
化学式(III)的化合物,其中R1、R2、R3和R4如描述中所定义。