Stereocontrolled syntheses of the diastereoisomeric 6-(1-hydroxyethyl)-2-ethylthio and 2-(2-aminoethylthio)-penem-3-carboxylates from a common monocyclic azetidinone precursor are described. Cu (I)-promoted cyclisation of suitable N/C-3 secopenems is shown to yield “isopenems” (7-oxo-2-thia-1-azabicyc1o[3.2.0]-hept-3-enes) as the sole bicyclic product.
描述了由常见的单环氮杂
环丁酮前体的非对映异构体6-(1-羟乙基)-2-乙
硫基和2-(2-
氨基乙
硫基)-penem-3-
羧酸酯的立体控制合成。
铜(I)促进合适的N / C-3 secopenems的环化反应可产生“ isopenems”(7-氧代-2-thia-1-azabicyc10o [3.2.0]-庚-3-烯)作为唯一的双环产品。