Synthesis of 1,2-diazetidinones (aza-β-lactams) by photochemical ring contraction
作者:Geoffrey Lawton、Christopher J. Moody、Christopher J. Pearson
DOI:10.1039/p19870000877
日期:——
the presence of alcohols, diethylamine, or water gives 1,2-diazetidinones (12) formed by photochemical Wolff rearrangement with ring contraction followed by reaction of the resulting ketene with the nucleophile. In the case of the bicyclic diazo compound (11d) a fragmentation reaction competes with ring contraction. The aza-β-lactams (12) show the expected high frequency carbonyl stretch in their i.r
在醇,二乙胺或水的存在下辐照4-重氮吡唑烷-3,5-二酮(11)产生1,2-二氮杂二酮(12),其通过光化学Wolff重排与环收缩形成,然后使所得的烯酮与亲核试剂。在双环重氮化合物(11d)的情况下,断裂反应与环收缩竞争。氮杂-β-内酰胺(12)在其红外光谱中显示出预期的高频羰基拉伸。酸(12e)易于脱羧得到4-未取代的1,2-二苄基二氮杂二酮(28),其四元环通过碱水解,氢化铝锂或乙硼烷裂解得到(29),(30)和(31)(方案9)。将(12e)的羧基取代基修饰成酰氨基的尝试是失败的。