29547-04-4Relevant articles and documents
Trispirododecane-4,8,12-trione and Other Oligomers of Carbonylcyclopropane. The Organozinc Route
Hoffmann, H. Martin R.,Eggert, Ulrike,Walenta, Angela,Weineck, Edeltraut,Schomburg, Dietmar,et al.
, p. 6096 - 6100 (1989)
1-Bromocyclopropanecarboxylic acid (8) and its chloride (9) were prepared from γ-butyrolactone on a 20-100-g scale.Dehalogenation of 9 with zinc-copper couple in acetonitrile gave not only the known dispiro octane-4,8-dione (3) but also the aesthetically pleasing title compound 10 and 6-cyclopropylidene-5-oxaspirohexan-4-one (11) as well as tetracyclic α-alkylidene-γ-butyrolactone 12, i.e., 3-(oxodispirooctan-4-ylidene)tetrahydro-2-furanone. "Zinc carbon enolate" 13a is considered to be an important intermediate en route to 10 in solventacetonitrile.The X-ray crystal structure of 10 shows the molecule to be nearly planar with very short distal cyclopropane carbon-carbon bonds .
Synthesis of optically active 2-substituted azetidine-2-carbonitriles from chiral 1-arylethylamineviaα-alkylation ofN-borane complexes
Nakanome, Nobuhiro,Tayama, Eiji
, p. 23825 - 23837 (2021/07/14)
The base-promoted α-alkylation ofN-((S)-1-arylethyl)azetidine-2-carbonitriles3viaformation of theirN-borane complexes4was investigated. For example, treatment of diastereomerically pure boraneN-((S)-1′-(4′′-methoxyphenyl)ethyl)azetidine-2-carbonitrile complex (1S,2S,1′S)-4bwith 1.2 equivalents of LDA at ?78 °C followed by 1.3 equivalents of benzyl bromide at ?78 °C and warming to room temperature produced α-benzylated (2S,1′S)-5bain 72% yield and (2R,1′S)-5bain 2% yield. A mechanism for this diastereoselective α-alkylation was proposed. Our method enables the production of optically active 2-substituted azetidine-2-carbonitriles, such as α-benzylated (S)-10aand (R)-10a, starting from commercially available (S)-(1-(4-methoxyphenyl)ethyl)amine.
Synthesis method of 5-fluoro-2-(1-bromocyclopropyl) pyridine
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Paragraph 0016; 0017; 0027; 0028; 0038; 0039, (2019/08/01)
The invention relates to a synthesis method of 5-fluoro-2-(1-bromocyclopropyl) pyridine. 1,4-butyrolactone, ethyl 4-bromobutyrate and 5-fluoro-2-mercaptopyridine are used as raw materials to prepare 5-fluoro-2-(1-bromocyclopropyl) pyridine through eleven steps of reaction. A synthetic route of the 5-fluoro-2-(1-bromocyclopropyl) pyridine is as follows: (as described in the specification). The invention has the advantages that the synthesis method of 5-fluoro-2-(1-bromocyclopropyl) pyridine improves the yield and provides an efficient synthesis method for the synthesis of the compound.
An efficient synthesis of 1-bromo-1-cyanocyclopropane
Xue, Feng,Li, Chang-Gong,Zhu, Yong,Lou, Tian-Jun
, p. 418 - 419 (2014/08/05)
An efficient process for the synthesis of 1-bromo-1-cyanocyclopropane has been developed starting from inexpensive γ-butyrolactone via bromination, cyclisation, ammoniation and dehydration reaction. The sequence proceeds in good yield.