作者:Pablo Wessig、Olaf Mühling
DOI:10.1002/hlca.200390086
日期:2003.3
trisubstituted cyclopropyl ketones 11 were prepared by irradiation of ketones 3 and 5, which bear a leaving group adjacent to the carbonyl C-atom. The required ketones 3 could be easily synthesized either by functionalization of ketones 1 with a hypervalent iodine reagent, 2, or by O-sulfonylation of α-hydroxy ketones 7. The nitrates 5 were obtained by treatment of the corresponding α-bromo ketones with AgNO3
通过辐射酮3和5制备一系列二和三取代的环丙基酮11,所述酮3和5带有与羰基C-原子相邻的离去基团。所需的酮3可以通过使用高价碘试剂2对酮1进行功能化或通过α-羟基酮7的O-磺酰化来轻松合成。通过用AgNO 3处理相应的α-溴代酮获得硝酸盐5。3和5的照射必须在除酸剂(1-甲基-1 H-咪唑)的存在下进行,以获得高收率的环丙烷11。除其他事项外,该方法的合成效率通过制备高收率的高应变双环[2.1.0]戊烷11i得以证明。通过光动力学测量以及量子化学计算研究了光化学环化的机理。已经表明,离去基团的存在实质上影响了光化学反应级联的所有步骤。还确定了11j和exo - 11k的X射线晶体结构。