摘要:
Enolate salts of 4-fluoro-2-hydroxymethylene-3-oxobutyrates of formula wherein R1 is C1-10 alkyl, R2 and R3 are independently hydrogen or fluorine, M is an alkali or alkaline earth metal, and n is 1 or 2, are prepared from enolate salts of the corresponding 4-fluoro-3-oxobutyrates and carbon monoxide. The enolate salts of formula I can be alkylated or acylated to obtain the corresponding enol ethers and esters. The 4-fluoro-3-oxobutyrate starting material can be prepared from 1,1-difluoroethyl methyl ethers by SbF5-catalyzed fluoromethane elimination followed by halogen exchange with lithium chloride, reacting the thus obtained fluoroacetyl chloride with ketene and quenching with the appropriate alcohol R1-OH.
摘要:
NEW MATERIAL:A compound shown by the formula I [R is carboxy-protecting group; R 1 is (substituted)alkyl, aralkyl, or allyl; X is oxo, or (substituted)methylene; with the proviso that double bond =X may be transferred into the ring to form 3-cephem ring]. EXAMPLE: 7α-Benzamido-3-methylene-1-dethia-1-oxacephem-4α-carboxylic ester. USE: An intermediate for synthesizing 1-oxacephem antibacterial antibiotic, etc. PROCESS: For example, an oxazolinoazetidinone compound shown by the formula II(Z is H, or amino-protecting group) is reacted with diazobutyric ester compound shown by the formula III (Y is halogen, or hydroxy), and, if necessary, the amino-protecting group is removed to give 2-diazo-3-substituted-4-(2-oxo-3-amidoazetidin-4-yl)oxybutyric ester shown by the formula IV, which is subjected to carbenoid insertion reaction to give a compound shown by the formula I . COPYRIGHT: (C)1984,JPO&Japio
摘要翻译:新材料:由式I表示的化合物[R是羧基保护基; R 1是(取代的)烷基,芳烷基或烯丙基; X是氧代,或(取代的)亚甲基; 条件是双键= X可以转移到环中以形成3-头孢烯环]。 实施例:7α-苯甲酰氨基-3-亚甲基-1-脱硫-1-氧代四氢-β-木糖酸酯。 用途:合成1-氧硫氨酸抗菌抗生素等的中间体。方法:将式Ⅱ所示的恶唑啉氮酮酮化合物(Z为H或氨基保护基)与式Ⅲ所示的重氮异丁酸酯化合物 Y是卤素或羟基),如果需要,除去氨基保护基,得到2-重氮基-3-取代-4-(2-氧代-3-氨基吖丁啶-4-基)氧基丁酸酯 式IV,其进行碳插入反应,得到式I所示的化合物。
摘要:
Production of organic compounds (I) having a low content of hydrolyzable fluoride (HLF) involves contacting HLF-contaminated (I) with a removing agent for HLF selected from inorganic oxide sorbents (II) and onium salts (III) of carboxylic acids. An Independent claim is also included for 4-chloro-4,4-difluoroacetoacetic acid, 4,4-difluoroacetoacetic acid and their onium salts.