New methylene homologation method for cyclic ketones.
Teaching new tricks to an old dog: By intercepting adducts between ketones and lithium trimethylsilyldiazomethane, a new Tiffeneau-Demjanov type methylene homologation could be realized in a single-step operation. Among proton sources and Lewis acids, silica gel was found to be the most effective reagent for the protonation of intermediates and their subsequent ring expansion (see scheme).
Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607, USA.
Huaqing
H
Liu
Chunrui
C
Sun
Nam-Kyu
NK
Lee
Roger F
RF
Henry
Daesung
D
Lee
D002384:Catalysis; D003978:Diazomethane / Q000031:analogs & derivatives* / Q000737:chemistry; D007659:Ketones / Q000737:chemistry*; D058116:Lewis Acids / Q000737:chemistry*; D008094:Lithium / Q000737:chemistry*; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry*; D015394:Molecular Structure; D011522:Protons; D014297:Trimethylsilyl Compounds / Q000737:chemistry*
D007659:Ketones; D058116:Lewis Acids; D011522:Protons; D014297:Trimethylsilyl Compounds; D003978:Diazomethane; D008094:Lithium; D008697:Methane; C060070:trimethylsilyldiazomethane