Synthesis of β-oxo carbonyl and thiocarbonyl compounds via basic sulfur abstraction
作者:Saúl Silva、Christopher D. Maycock
DOI:10.1016/j.tet.2019.130552
日期:2019.10
suitable thioesters represents a mild method for the formation of carbon-carbon bonds and the formation of 1,3-dicarbonyl compounds. A study of the scope and limitations of this reaction for the synthesis of these or mixed 1,3-carbonyl/thiocarbonyl compounds by a base promoted sulfur abstraction rearrangement is described. These reactions were typically very clean and the products were obtained in good
Kinetically distinct triplets in the photorearrangement of 2-phenylcyclohexanone to cis- and trans-6-phenyl-5-hexenals
作者:Peter J. Wagner、Thomas J. Stratton
DOI:10.1016/s0040-4020(01)92379-8
日期:——
an almost concerted out-of-plane cleavage which forms a 1,6-biradical in the perfect geometry for disproportionation to trans-enal.The precursor to cis-enal may be a minor rotamer of 1 which is forced by nonbonded interactions into a cleavage mode which twists the biradical into a geometry suitable for at least partial formation of cis-enal. In both cases biradicals must be very short-lived and not
Novel triazolocycloalkylthiadiazines, their preparation, and use as antisecretory agents and central nervous system depressants.
小说三唑环烷基噻二嗪,它们的制备以及作为抗分泌剂和中枢神经系统抑制剂的用途。
Triazolocycloalkylhydrothiadiazine derivatives
申请人:Richardson-Merrell Inc.
公开号:US03954981A1
公开(公告)日:1976-05-04
Novel triazolocycloalkylhydrothiadiazines and their preparation, which are useful as antisecretory agents, central nervous system stimulants, and central nervous system depressants, are disclosed.
Axial equatorial populations were determined for (E)-2-X-cyclohexanone oximes and O-methyl oxime ethers in chloroform by the Eliel method [X = F, Cl, Br, OCH3, N(CH3)(2), SCH3]. A novel approach is presented, which uses H-1 NMR data from the protons bonded to C-6. The conformational proportions were also obtained from the C-4 chemical shifts, the Z-isomer spectral parameters being taken as reference for calculation. For both series, all substituents adopt preferentially the axial conformation (86-96%), but the O-methyl oxime ethers present an enhanced axial population compared with the corresponding oximes, owing to the accepted occurrence of a pi(C=NOH)/sigma(CX)* stabilizing interaction. Copyright (C) 2000 John Wiley & Sons, Ltd.