2-Substituted 2,3-Dihydro-4<i>H</i>-1,3-benzoxazin-4-ones: Novel Auxiliaries for Stereoselective Synthesis of 1-β-Methylcarbapenems<sup>1</sup>
作者:Kazuhiko Kondo、Masahiko Seki、Tooru Kuroda、Takeshi Yamanaka、Tameo Iwasaki
DOI:10.1021/jo961866j
日期:1997.5.1
The dihydrobenzoxazone 9e, which is easily prepared from salicylamide 11 and cyclohexanone, serves as an efficient auxiliary in the synthesis of the 1-beta-methylcarbapenem key intermediate 10. The stereocontrolled Reformatsky-type reactions of the acetoxyazetidinone 2 with the carboximides 6 gave the intermediates 7 with high diastereoselectivities in high chemical yields. The auxiliary 9e also acts
容易由水杨酰胺11和环己酮制得的二氢苯并恶唑酮9e在合成1-β-甲基卡巴培南关键中间体10时用作有效的助剂。乙酰氧基氮杂环丁酮2与羧酰亚胺6的立体控制的Reformatsky型反应得到了中间体7具有高非对映选择性,化学收率高。辅助9e在TMSC1促进的Dieckmann型环化中还充当良好的离去基团,导致1-β-甲基卡巴培南骨架。通过使用该助剂,合成了10种化合物,总产率为58%,从2开始需四个步骤。