Upon treatment with various organolithiums, 4-acetoxyazetidin-2-one (10) afforded the corresponding carbondisplaced compounds (11), (12), and (13). 4-(3-Diazo-3-ethoxycarbonyl-2-oxopropyl)azetidin-2-one (15) was also synthesised from (10) and ethyl α-diazoacetoacetate in the presence of lithium hexamethyldisilazide in one step. The diazo-compound (15) was thermally cyclised to the bicyclic keto-ester
4-Substituted 2-azetidinones were obtained in excellent yields from the reaction of various cuprates with 4-acetoxy-2-azetidinone.
从各种铜酸盐与4-乙酰氧基-2-氮杂环丁酮的反应中,以优异的产率获得了4-取代的2-氮杂环丁酮。
A new method for the carbon-extension reactions of azetidin-2-ones at the 4-position
作者:Takeo Kobayashi、Noboru Ishida、Tetsuo Hiraoka
DOI:10.1039/c39800000736
日期:——
High yields of 4-alkyl-, 4-allyl-, 4-vinyl-, or 4-ethynyl-azetidin-2-ones are obtained by treating 4-sulphonylazetidin-2-ones with either lithium organocuprates or Grignard reagents, but yields from 4-acetoxyazetidin-2-one with Grignard reagents are low.
Palladium-Catalyzed Intramolecular Insertion of Alkenes into the Carbon–Nitrogen Bond of β-Lactams
作者:Akira Yada、Satoshi Okajima、Masahiro Murakami
DOI:10.1021/jacs.5b05308
日期:2015.7.15
The carbon-nitrogen bond of beta-lactams is cleaved by palladium(0), and an alkene is intramolecularly inserted therein. The following reductive elimination produces nitrogen-containing benzo-fused tricycles in good to high yields.