A New Synthesis of 1β-Alkylcarbapenems Utilizing Eschenmoser Sulfide Contraction of the Novel Thiazinone Intermediates
作者:Osamu Sakurai、Tsuyoshi Ogiku、Masami Takahashi、Masahito Hayashi、Takeshi Yamanaka、Hiroshi Horikawa、Tameo Iwasaki
DOI:10.1021/jo960764q
日期:1996.1.1
Novel syntheses of the 1,beta-alkylcarbapenems were achieved on the basis of Eschenmoser sulfide contraction via the new bicyclic 1,3-thiazinone intermediates. 1,3-Thiazinones 7, 16, and 25 were effectively prepared from thioesters 5 and 22 using a C4-S bond formation process. The sulfide contraction reactions were performed by treatment of 7, 16, and 25 with base (NaH or KO-t-Bu) in the presence of triphenylphosphine to generate the corresponding carbapenem enolate 12, 17, and 26, which were trapped by (PhO)(2)POCl followed by the reaction with mercaptans to afford carbapenems 10a, 10b, 19, and 28, respectively.