Annulation Reactions of Allenyl Esters: An Approach to Bicyclic Diones and Medium-Sized Rings
作者:Bilal A. Bhat、Samantha L. Maki、Elijah J. St.Germain、Pradip Maity、Salvatore D. Lepore
DOI:10.1021/jo501700c
日期:2014.10.3
approach to construct sterically congested bicyclo-alkenedione frameworks is reported. Under the action of potassium carbonate, α-sulphonyl cycloalkanones are added to functionalized allenyl esters, leading to a lactone intermediate that is subsequently reduced to initiate an intramolecular aldol cyclization to [3.2.1], [3.3.1], and [4.3.1] bicycles. Oxidation then affords bicyclic diones in good three-step
Reaction of β-keto sulphones with 2N NaOH, at 70°C, in aqueous media and in presence of cetyltrimethylammonium chloride (CTACl), produces the CC bond fission between the carbonyl group and the carbon bearing the sulphone.
Transition-metal-free insertion of alkynes into the C–C σ-bond of cyclic β-keto sulfones: an atom-economical way to medium-size-ring sulfonyl derivatives
作者:Yingge Gu、Yajie Yang、Ye Wang、Zongkang Wang、Yilin Zhu、Yanzhong Li
DOI:10.1039/d2nj01197b
日期:——
efficient strategy for the preparation of medium-size-ring sulfonyl derivatives has been developed. This method is realized by alkynes insertion into the C–C σ-bond of cyclic β-keto sulfones, introducing sulfonyl groups into medium-size-ring compounds. This reaction possesses competitive features such as broad substrate scope, transition-metal-free and atom economy.
Dynamic kinetic resolution in the baker's yeast mediated reduction of 2-Benzenesulfonylcycloalkanones
作者:Anita R. Maguire、Noreen O'Riordan
DOI:10.1016/s0040-4039(99)01947-4
日期:1999.12
2-Benzenesulfonylcyclopentanone 1 and -cyclohexanone 2 undergo efficient dynamic kinetic resolution on treatment with baker's yeast, under a range of conditions including in organic solvents, to form the corresponding cis-2-benzenesulfonylcycloalkanols 5 and 6 in excellent enantiopurity. Reduction of larger ring derivatives is much less efficient. (C) 1999 Elsevier Science Ltd. All rights reserved.
Cyclocontraction - spiroannulation: a stereoselective approach to spirocycles