150982-68-6Relevant academic research and scientific papers
Regioselective transformation of alkynes into cyclic acetals and thioacetals with a gold(I) catalyst: comparison with Br?nsted acid catalysts
Santos, Laura L.,Ruiz, Violeta R.,Sabater, Maria J.,Corma, Avelino
, p. 7902 - 7909 (2008/12/21)
Au(I) catalyzes the transformation of alkynes into cyclic acetals and thioacetals at much higher rate than Br?nsted acids. The reaction appears to be general for a range of alkynes and diols or dithiols, which are efficiently transformed with high selectivities. One of the salient features of this reaction process is the high reactivity of the enol ether or enol thioether intermediates, which undergo a rapid isomerization reaction to afford the cyclic acetals or thioacetals, so that isolation or subsequent activation processes are not required. This type of reactions allows us to synthesize a series of fragrances.
Photochemical preparation of highly functionalized 1-indanones
Wessig, Pablo,Glombitza, Clemens,Mueller, Gunnar,Teubner, Janek
, p. 7582 - 7591 (2007/10/03)
A series of o-alkylphenyl alkyl ketones 1 were synthesized by different methods. The presence of a leaving group X adjacent to the carbonyl group is the special peculiarity of these ketones. Upon irradiation the keto carbonyl group of these compounds undergoes an n-π* excitation followed by a 1,5-hydrogen migration from the o-alkyl substituent to the carbonyl oxygen atom. The thus formed 1,4-diradicals are subject to a very rapid elimination of acid HX, giving 1,5-diradicals. We called this process spin center shift. After intersystem crossing these diradicals cyclize to 1-indanones 20 in good yields. Depending on the solvent and on substituents, o-alkoxyalkyl ketones 22 or benzo-[c]furanes 21 are obtained as byproducts. The mechanism of the cyclization was elucidated by quantum chemical calculations and kinetic measurements.
Synthesis of the Integrastatin Nucleus Using the Ramberg - Baecklund Reaction
Foot, Jonathan S.,Giblin, Gerard M. P.,Taylor, Richard J. K.
, p. 4441 - 4444 (2007/10/03)
(Equation presented) The first synthesis of the tetracyclic nucleus of the Integrastatins, natural products that have been shown to selectively inhibit HIV-1 integrase, is reported. Key steps of this synthesis involve a novel cis-selective Ramberg-Baecklund reaction and an unusual Lewis acid-promoted cyclization step.
Protoberberines from Reissert compounds, II: A new synthesis of 8-methyldibenzo[a,g]quinolizidines
Reimann,Renz
, p. 253 - 258 (2007/10/02)
The Reissert compounds 16 are benzylated by 2-bromomethylacetophenone dioxolane 14 to give the dihydroisoquinolines 5. Treatment of 5 with KOH yields the 1-benzylisoquinolines 6 which spontaneously form the deoxygenated coralynes 4 in acidic solution. 4a
