156049-95-5Relevant academic research and scientific papers
Photochemistry of Structural Analogues of Previtamin D3: Generality of the Wavelength-Dependent Triene Photocyclization
Dauben, William G.,Zhou, Boli,Lam, Joe Y. L.
, p. 9005 - 9008 (2007/10/03)
Two structural previtamin D3 analogues (R = H, CH3) cyclized photochemically with a 1.4-1.8-fold increase in quantum yields over a 3-nm change in excitation wavelength. The sudden increase in quantum yields is due to the participation and mixing of both 2A and 1B excited states. At λ ≤ 306 nm, the 1B state is initially excited and then (a) partitions between isomerization to the corresponding trans triene isomers, (b) decays to the 2A state to give the corresponding cyclohexadienes, and (c) decays to the ground state. At λ ≥ 309 nm, the 2A state is directly excited to give the corresponding cyclohexadienes and the relaxation path from 1B state to the ground state or isomerization in the 1B state is diminished.
An efficient Julia olefination mediated by magnesium in ethanol
Lee, Ge Hyeong,Lee, Hyeon Kyu,Choi, Eun Bok,Kim, Bum Tae,Pak, Chwang Siek
, p. 5607 - 5608 (2007/10/02)
Reductive elimination step of Julia olefination was conveniently achieved by using magnesium powder in absolute ethanol in the presence of catalytic amount of mercuric chloride at room temperature to give the corresponding alkenes in almost quantitative yields.
Stereochemistry of direct olefin formation from carbonyl compounds and lithiated heterocyclic sulfones
Baudin, J. B.,Hareau, G.,Julia, S. A.,Lorne, R.,Ruel, O.
, p. 856 - 878 (2007/10/02)
The conditions for the title reaction were studied for the 2-benzothiazole and 2-pyridine series and for some examples in the 2-pyrimidine series.The olefin preparations were generally observed to be more efficient for 2-BT-sulfone systems.From the data of the hundred cases studied, it can be concluded that (E)-olefins are obtained: (i) from saturated BT-sulfones and aromatic aldehydes; and (ii) from benzylic BT-sulfones and branched saturated aldehydes (isobutyraldehyde, pivalaldehyde) or α,β-ethylenic or aromatic aldehydes. (Z)-olefins arise: (i) fom propargylic BT-sulfones and saturated or aromatic aldehydes; and (ii) from allylic or benzylic Pyr-sulfones and saturated aldehydes.Possible mechanisms for this new olefination procedure were examined. - heteroaromatic sulfones, organolithium derivatives, intramolecular ipso reactions, stereochemistry, elimination, olefination.
