145237-56-5Relevant academic research and scientific papers
Efficient Access to All-Carbon Quaternary and Tertiary α-Functionalized Homoallyl-type Aldehydes from Ketones
Pace, Vittorio,Castoldi, Laura,Mazzeo, Eugenia,Rui, Marta,Langer, Thierry,Holzer, Wolfgang
supporting information, p. 12677 - 12682 (2017/09/08)
β,γ-Unsaturated aldehydes with all-carbon quaternary or tertiary α-centers were rapidly assembled from ketones through a unique synthetic operation consisting of 1) C1 homologation, 2) Lewis acid mediated epoxide–aldehyde isomerization, and 3) electrophilic trapping. The synthetic equivalence of a vinyl oxirane and a β,γ-unsaturated aldehyde is the key concept of this previously undisclosed tactic. Mechanistic studies and labeling experiments suggest that an aldehyde enolate is a crucial intermediate. The homologating carbenoid formation plays a critical role in determining the chemoselectivity.
Photochemistry of some allenic counterparts of cyclohexenones and 2,5-cyclohexadienones
Zimmerman, Howard E.,Baker, Mark R.,Bottner, Robert C.,Morrissey, Michael M.,Murphy, Sean
, p. 459 - 466 (2007/10/02)
Allenic analogs of 4,4-diphenylcycIohexenone and a similar counterpart of 4,4-diphenyl-2,5-cyclohexadienone were synthesized. These molecules have a 2-electron π-MO perpendicular to the six-ring π-system. This perpendicular π-orbital is analogous to the oxygen py orbital which is orthogonal to the carbonyl π-bond. The photochemistry of the allenic systems was explored with the finding that the triplets were unreactive and the singlets underwent a phenyl migration to form bicyclic photoproducts whose structures were established by spectral means, degradation, and independent synthesis. Excited states involving appreciable out-of-plane to π or π to out-of-plane excitations are defined as π- * and -π*, respectively. MNDO-CI level and CASSCF ab initio computations with geometry optimization were carried out with the objective of determining the role of -π* and π-* transitions and for comparison with the experimental results.
