23116-94-1Relevant articles and documents
Diversity oriented approach to crownophanes by enyne metathesis and Diels-Alder reaction as key steps
Kotha, Sambasivarao,Waghule, Gopalkrushna T.
, p. 6314 - 6318 (2012)
Various crownophanes are assembled starting with simple phenol derivatives such as catechol, resorcinol, and hydroquinone. Here, cross-enyne metathesis (CEM) and Diels-Alder (DA) reaction have been used as key steps. This strategy has embedded six diversi
A study towards the regioselective synthesis of the e,e,e trisadduct of C60 via the [4+2] Diels-Alder reaction with tethers bearing orthoquinodimethane precursors
Ioannou, Charalambos P.,Chronakis, Nikos
, p. 65 - 82 (2015/04/21)
The regioselective synthesis of an e,e,e trisadduct of C60 via the Diels-Alder reaction with orthoquinodimethanes has been attempted employing the tether-directed remote functionalization approach. Opened-structure tether 10 and macrocyclic tethers 16 and 21 were synthesized for this purpose. The functionalization of C60 afforded inseparable mixtures of regiomeric trisadducts and the regioselective formation of the e,e,e trisadduct was not feasible even when the more preorganized tethers 16 and 21 were employed. The in situ thermal generation of orthoquinodimethanes from the 1,2-bis(bromomethyl)benzene precursors requires high temperatures and is followed by fast, irreversible cycloaddition with C60 to afford thermally stable products, which prevents the achievement of high regioselectivities.
Application of Bayer-Villiger reaction to the synthesis of dibenzo-18-crown-6, dibenzo-21-crown-7 and dihydroxydibenzo-18-crown-6
Utekar, Druman R.,Samant, Shriniwas D.
, p. 193 - 197 (2014/05/06)
Dibenzo-18-crown-6, dibenzo-21-crown-7 and dihydroxy dibenzo-18-crown-6 were synthesized by Bayer-Villiger oxidation strategy. Dibenzo-18-crown-6 and dibenzo-21-crown-7 could be synthesized through a three-step protocol starting from salicylaldehyde. Salicylaldehyde was reacted with bis-(2-chloroethyl)ether using K2CO3 in acetonitrile to link the two phenolic groups with the oxyethylene bridge followed by conversion of the formyl group to the hydroxy group via a Baeyer-Villiger reaction and finally linking the two phenolic group with appropriate oxyethylene bridge. The two target crown ethers were obtained in overall yield, 24% and 30%, respectively. This method has a great potential for synthesis of symmetrical as well as unsymmetrical dibenzo crowns with varying oxyethylene bridges. Baeyer-Villiger oxidation could be used to prepare dihydroxy derivative of dibenzo-18-crown-6 through acetylation of dibenzo-18-crown-6 followed by Baeyer-Villiger oxidation. The Baeyer-Villiger oxidation could be substantially accelerated using trifluoroacetic acid.