- An anti-tetraamination of a 1,3-diene unit via cascade annulations of the azulenone scaffold with dicarbonyl azo-compounds
-
Dense and stereo-controlled integrations of C-N bonds on the azulenone scaffold are achieved by sequential (i) ene, (ii) [6+2]-cycloaddition, and (iii) hetero-conjugate addition reactions leading to a topologically complex bis-bridged skeleton.
- Ishigaki, Yuhei,Mahendar, Velisoju,Oguri, Hiroki,Oikawa, Hideaki
-
-
Read Online
- New results in homoheptalene chemistry
-
The thermal reaction of homoazulene (= bicyclo[5.3.1]undeca-1,3,5,7,9-pentaene; 2) with dimethyl acetylenedicarboxylate (ADM) in 1,2-dichloroethane (ClCH2CH2Cl) results, in contrast to an earlier report [5], in formation of not only
- Rueedi, Georg,Hansen, Hans-Juergen
-
p. 1017 - 1047
(2007/10/03)
-
- Selective bond cleavage of [5.3.1]propellanes by lead tetraacetate: A facile entry into the carbocyclic frame [A,B ring] of taxol
-
[5.3.1]Propellanes e.g., the tricyclo[5.3.1.01,7]undeca-2,4-dien-10-one 8 and the corresponding methylidene compound 10 were prepared from methyl cinnamate 2 in several steps involving rhodium(II) acetate mediated cyclization of 4 to 6 as a key step. The selective central cyclopropyl bond cleavage in 8 and 10 by lead tetraacetate provides the basis of a new approach to the construction of carbocylic frame of A,B ring of Taxol.
- Kumar, Pradeep,Rao, Ashok T.,Saravanan,Pandey, Bipin
-
p. 3397 - 3400
(2007/10/02)
-
- The Intramolecular Buchner Reaction of Aryl Diazoketones. Substituent Effects and Scope in Synthesis
-
Rhodium(II) acetate-catalysed cyclisation of α-diazoketones derived from 3-arylpropionic acid produces bicyclodecatrienones or 2-tetralones depending on the substitution pattern of the aryl ring in the precursor; the former products are transformed into the latter catalytically with trifluoroacetic acid.Precursors with methyl, methoxy, and acetoxy substituents have been examined, efficient cyclisation occurring in all cases.When the precursor contains a meta-methoxy substituent, 2-tetralones are obtained directly.The efficient conversion of 3-phenylpropionicacid into trans-1-methylbicyclodecan-2-one is also described, partial asymmetric synthesis having been realised through the use of rhodium (S)-mandelate as the cyclisation catalyst.Cyclisations of diazoketones derived from 4-phenylbutyric acid and 5-phenylpentanoic acid have also been studied; the former provides a new entry into the bicycloundecane system whereas the latter produces a 2,3-disubstituted cyclopentanone via C-H insertion.Aspects of the cycloheptatriene-norcaradiene equilibrium in fused ring systems are discussed.
- Kennedy, Michael,McKervey, M. Anthony,Maguire, Anita R.,Tuladhar, Sarbajna M.,Twohig, M. Fiona
-
p. 1047 - 1054
(2007/10/02)
-
- Efficient Synthesis of Bicyclodecatrienones and of 2-Tetralones via Rhodium(II) Acetate-catalysed Cyclisation of α-Diazoketones derived from 3-Arylpropionic Acids
-
Rhodium(II) acetate-catalysed cyclisation of α-diazoketones derived from 3-arylpropionic acids produces bicyclodecatrienones or 2-tetralones depending on the substitution pattern of the aryl ring; the former products are transformed into the latter by catalytic amounts of trifluoroacetic acid.
- McKervey, M. Anthony,Tuladhar, Sarbajna M.,Twohig, M. Fiona
-
p. 129 - 130
(2007/10/02)
-
- A Short New Azulene Synthesis
-
A short new azulene synthesis requiring no dehydrogenation step, has been developed (Scheme 1).Intramolecular carbene addition creates the bicyclic ring system of azulene with a high degree of unsaturation and versatile functionality in a single step from a simple benzene derivative.The synthesis is particularly amenable to preparation of specific 13C- and 2H-labeled azulenes.
- Scott, Lawrence T.,Minton, Mark A.,Kirms, Mark A.
-
p. 6311 - 6314
(2007/10/02)
-