15798-64-8Relevant academic research and scientific papers
Method for preparing Z-isomer by E-isomer of alpha, beta-nonsaturated carbonyl compound
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Paragraph 0052; 0053, (2017/04/29)
The invention provides a method for preparing a Z-isomer by an E-isomer of an alpha, beta-nonsaturated carbonyl compound. The method uses nitrogen-containing chiral binaphthol phosphoramidite to prepare a catalyst, under mild reaction condition, the E-isomer of the alpha, beta-nonsaturated carbonyl compound is efficiently conversed to the Z-isomer. The method is especially suitable for preparing neral through isomerization of partial geranial in a citral split residual material, the citral with mol ratio of the obtained geranial to neral being 1:1 can be reused for splitting the neral, raw material utilization rate is increased, and the cost is reduced.
Isomerization and dissociation of 2,3-dihydrofuran (2,3-DHF) induced by infrared free electron laser
Matsubara,Osada,Nakajima,Imai,Nishimura,Oyama,Tsukiyama
, p. 53 - 59 (2016/04/26)
We investigated infrared multiphoton dissociation and isomerization reactions of 2,3-dihydrofuran (2,3-DHF), cyclopropanecaboxaldehyde (CPCA) and crotonaldehyde (CA) with free electron laser at Tokyo University of Science (FEL-TUS). From 2,3-DHF as a starting material, CPCA and CA were the main isomerization products. From the measured [CPCA]/[CA] ratio, the equivalent temperature for the vibrationally hot 2,3-DHF was estimated to be 1300-1500 K. From CPCA, both 2,3-DHF and CA were detected as isomerization products. No isomerization reaction from trans-CA to CPCA and 2,3-DHF was recognized and the dissociation to propylene was the dominant process. The experimentally identified reaction pathways are well explainable by quantum chemical calculations at the MP2/cc-pVDZ level.
Total synthesis and biological evaluation of (-)-exiguolide analogues: Importance of the macrocyclic backbone
Fuwa, Haruhiko,Mizunuma, Kana,Sasaki, Makoto,Suzuki, Takaya,Kubo, Hiroshi
supporting information, p. 3442 - 3450 (2013/07/05)
(-)-Exiguolide (1), isolated from the marine sponge Geodia exigua, has been shown to inhibit the growth of the A549 human lung adenocarcinoma and NCI-H460 human lung large cell carcinoma cells in vitro. In this study, we synthesized structural analogues o
An experimental (flash vacuum pyrolysis) and theoretical study of the tautomerism of pyrazolinones at high temperatures
Yranzo, Gloria I.,Moyano, Elizabeth L.,Rozas, Isabel,Dardonville, Christophe,Elguero, Jose
, p. 211 - 216 (2007/10/03)
Flash vacuum pyrolysis experiments were carried out between 500 and 800°C on 3(5)-phenyl- and 3(5)-methylpyrazolinones and on 3(5)-methoxy-5(3)-phenylpyrazole. The origin of the isolated products (mainly indanone, hydroxyalkynes and α,β-unsaturated aldehydes) can be explained as arising from the hydroxy tautomers of pyrazolinones. Temperature effects on the tautomeric equilibrium of 1-phenyl-3-methylpyrazolinone in solution show that the percentage of the CH tautomer increases with the temperature. MP2 ab initio calculations on the model compound, pyrazolinone itself, have been used to rationalize these findings. The problem of the aromaticity of the four tautomers of pyrazolinone has been examined through Schleyer's NICS (nuclear independent chemical shifts) calculations.
Synthesis of aromatic and αβ-unsaturated aldehydes by a friedel-crafts-like electrophilic destamylation using 1,1-dichloromethyl metyhyl ether
Niestroj, Michael,Neumann, Wilhelm P.
, p. 45 - 51 (2007/10/02)
A mild and effective method for the preparation of a variety of aromatic (7a-m), heteroaromatic (7n-r), and α,β-unsaturated aldehydes (8a-f) is described. The reaction of trialkylaryl- (2a-o), heteroaryl- (2p-t), and 1-alkenylstannanes (4a-f and 5a-f) with dichloromethyl methyl ether (1, DCME) in the presence of aluminium trichloride followed by hydrolysis provides the corresponding aldehydes. In the case of arylstannanes the ipso-isomers are generally formed; the p-alde-hydes occur as side products. The electrophilic substitution of 1-alkenylstannanes with 1 leads to α,β-unsaturated aldehydes In an ipso- and stereospecific manner. A comparison of the leaving abilities of the stannyl and silyl groups shows a lower or even zero reactivity of the silyl-substituted compounds 8a-e towards the electrophile 1. In the silylstannylalkene 6c only the stannyl group reacts whereas the stannyl function remains unaffected in the product, aldehyde 11.
Chemistry of Singlet Oxygen. 51. Zwitterionic Intermediates from 2,4-Hexadienes
O'Shea, Kevin E.,Foote, Christopher S.
, p. 7167 - 7170 (2007/10/02)
The three isomeric 2,4-hexadienes give nearly identical product distributions with singlet oxygen.Singlet oxygen causes rapid interconversion of the isomers, and methoxy hydroperoxides are formed from all three dienes in methanol (E,Z and Z,Z ca. 25 percent, E,E 10 percent).These observations are explained by intermediate zwitterions that revert to isomerized dienes in competition with collapse to products or capture by methanol.
STEREOSPECIFIC OXIDATION OF ALLYLIC ALCOHOLS
Al-Hassan, Mohammed I.
, p. 441 - 442 (2007/10/02)
Barium manganate has been found to be a convenient reagent for the oxidation of allylic alcohols to the isomerically pure products in excellent yields.
