Intermolecularradicaladdition reactions of α-iodo cycloalkenones and a synthetic study of the formal synthesis of enantiopurefawcettimine
作者:Kuan-Miao Liu、Chi-Min Chau、Chin-Kang Sha
DOI:10.1039/b714078a
日期:——
generation of alpha-carbonyl vinyl radicals from alpha-iodo cycloalkenones, the scope of their participation in intermolecular additionreactions with electron-withdrawing olefins are studied and a synthetic study of the formal synthesis of enantiopure fawcettimine using this reaction is described.
Simple method for α-alkylation of α,β-unsaturated enones through the Michael addition
作者:Ru Hwu Jih、Gholam H. Hakimelahi、Ching-Tai Chou
DOI:10.1016/s0040-4039(00)79017-4
日期:1992.10
Treatment of enones and Michael acceptors with a catalytic amount of 1,8-diazabicyclo[5.4.0]undec-7-ene in 1,3-dimethyl-2-imidazolidinone at 185 °C afforded the corresponding α-substituted enones in good yields.
A full account of the total synthesis of (±)-maistemonine, (±)-stemonamide, and (±)-isomaistemonine is presented. Two approaches have been developed to construct the basic pyrrolo[1,2-a]azepine core of the Stemona alkaloids, featuring a tandem semipinacol/Schmidt rearrangement of a secondary azide and a highly stereoselectively desymmetrizing intramolecular Schmidt reaction, respectively. To build
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
Use of epoxidation and epoxide opening reactions for the synthesis of highly functionalized 1-oxaspiro[4.5]decan-2-ones and related compounds
作者:Martin Eipert、Cäcilia Maichle-Mössmer、Martin E Maier
DOI:10.1016/j.tet.2003.08.010
日期:2003.9
provided the syn epoxide 12. By invoking chelation controlled epoxideopening the triol derivatives 13 and 14 or the spiro lactone 25 could be obtained. Elimination of HBr from the bromides 26 and 27 produced the spiro cyclohexenones 28 and 29. Epoxidation of the double bond occurred in a diastereoselective manner to give epoxides 30 and 31, respectively. Treatment of the epoxide 31 with LiBr/AcOH