609-08-5Relevant articles and documents
Synthesis, Electronic Spectroscopy, and Photochemistry of Methacrolein Oxide: A Four-Carbon Unsaturated Criegee Intermediate from Isoprene Ozonolysis
Vansco, Michael F.,Marchetti, Barbara,Trongsiriwat, Nisalak,Bhagde, Trisha,Wang, Guanghan,Walsh, Patrick J.,Klippenstein, Stephen J.,Lester, Marsha I.
, p. 15058 - 15069 (2019)
Ozonolysis of isoprene, one of the most abundant volatile organic compounds in the earth's atmosphere, generates the four-carbon unsaturated methacrolein oxide (MACR-oxide) Criegee intermediate. The first laboratory synthesis and direct detection of MACR-oxide is achieved through reaction of photolytically generated, resonance-stabilized iodoalkene radicals with oxygen. MACR-oxide is characterized on its first π? a? πelectronic transition using a ground-state depletion method. MACR-oxide exhibits a broad UV-visible spectrum peaked at 380 nm with weak oscillatory structure at long wavelengths ascribed to vibrational resonances. Complementary theory predicts two strong ?€? a? πtransitions arising from extended conjugation across MACR-oxide with overlapping contributions from its four conformers. Electronic promotion to the 11π? state agrees well with experiment, and results in nonadiabatic coupling and prompt release of O 1D products observed as anisotropic velocity-map images. This UV-visible detection scheme will enable study of its unimolecular and bimolecular reactions under thermal conditions of relevance to the atmosphere.
Dynamic Kinetic Resolution of I-Substituted Cyclic β-Ketoesters via Asymmetric Hydrogenation: Constructing Chiral Cyclic β-Hydroxyesters with Three Contiguous Stereocenters
Yang, Dan,Wu, Xiong,Zheng, Xiao-Jie,Xie, Jian-Hua,Zhou, Qi-Lin
supporting information, p. 5153 - 5157 (2021/07/20)
An efficient asymmetric hydrogenation of racemic I-substituted cyclic β-ketoesters via dynamic kinetic resolution to provide chiral cyclic β-hydroxy esters with three contiguous stereocenters is reported. Using a chiral spiro iridium catalyst (R)-5 (Ir-SpiroSAP), a series of racemic I-Aryl/alkyl substituted cyclic β-ketoesters were hydrogenated to the corresponding chiral cyclic β-hydroxy esters in high yields (84-97%) with good to excellent enantioselectivities (69->99% ee) and cis,cis-selectivities (up to >99:1).
Apple flavor compound, preparation method thereof and food additive
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Paragraph 0064-0066; 0081; 0082; 0086; 0090; 0091, (2020/07/13)
The invention relates to an apple flavor compound, a preparation method thereof and a food additive. The apple flavor compound has a structural formula shown as the specification, the apple flavor compound can be named as 1-(1-(1-(3, 3-dimethylcyclohexyl)ethyl)3-ethyl malonic acid malonate. Experiments prove that the compound has obvious mature sweet apple fragrance, can be used in food additiveswith apple fragrance, and provides a new source for the apple flavor compound.