Electrooxidative cleavage of carbon-carbon bonds. 2. Double cleavage of .alpha.,.beta.-epoxy alkanones and enantiospecific syntheses of chiral methyl trans- and cis-chrysanthemates from (+)- and (-)-carvones
Discovery of Unforeseen Energy-Transfer-Based Transformations Using a Combined Screening Approach
作者:Felix Strieth-Kalthoff、Christian Henkel、Michael Teders、Axel Kahnt、Wolfgang Knolle、Adrián Gómez-Suárez、Konstantin Dirian、Wiebke Alex、Klaus Bergander、Constantin G. Daniliuc、Bernd Abel、Dirk M. Guldi、Frank Glorius
DOI:10.1016/j.chempr.2019.06.004
日期:2019.8
photocatalysis. To this end, two energy-transfer-based cycloadditionreactions could be realized: a notably endergonic energy transfer process allows for the dearomative cycloaddition of benzothiophenes and related heterocycles. Moreover, by sensitization of enone moieties, a [2+2]-cycloaddition to alkynes and an unexpectedcycloaddition-rearrangement cascade were discovered. Advanced spectroscopic techniques
Borinic Acid/Halide Co-catalyzed Semipinacol Rearrangements of 2,3-Epoxy Alcohols
作者:Kashif Tanveer、Seung-Joon Kim、Mark S. Taylor
DOI:10.1021/acs.orglett.8b02248
日期:2018.9.7
A new mode of catalysis of the semipinacol rearrangement of 2,3-epoxy alcohols is described. In combination with a halide salt additive, diarylborinic acids promote a Type II rearrangement that occurs with net retention of configuration. This unusual stereochemical outcome is consistent with a mechanism involving regioselective ring opening of the epoxy alcohol by halide, followed by rearrangement
furnished the chiral bicyclo[2.2.2]octenones 6, 8 and 9 and 12 and 13 containing a bridgehead methyl group via an intramolecularalkylation reaction. In an analogous manner intramolecularalkylation reaction of the bromo enones 15a–e, obtained from carvone 2 by 1,3-alkylative enone transposition (→14) followed by a regiospecific bromoetherification reaction, furnished the bicyclo[2.2.2]oct-5-en-2-ones
A stereoselective total synthesis of (−)-seychellene
作者:A. Srikrishna、G. Ravi
DOI:10.1016/j.tet.2008.01.035
日期:2008.3
A stereoselective totalsynthesis of the tricyclic sesquiterpene (−)-seychellene, starting from (R)-carvone via (R)-3-methylcarvone has been accomplished, employing a combination of intermolecular Michael addition–intramolecular Michael addition sequence, a stereoselective hydrogenation, and an intramolecular alkylation reaction.