- A synthetic approach to perhydro-3-isoquinolinones bearing an angular methyl group via organocuprate addition
-
The addition of organocuprates to the activated C-C double bond in 2H-3,3a,4,5,6,7-hexahydro-2-indenone followed by trapping of the anionic intermediate with Mel as electrophile is reported. Structural assignment of the resulting product was carried out v
- Stanetty, Peter,Bahardoust, M. Hassan,Mihovilovic, Marko D.,Mereiter, Kurt
-
-
Read Online
- Palladium(0)-catalyzed reaction of cyclopropylidenecycloalkanes with carbon dioxide
-
Cyclopropylidenecycloalkanes, which are highly strained methylenecyclopropane (MCPs) containing a cycloalkane moiety, react with carbon dioxide smoothly to give the corresponding five-membered lactone derivatives in moderate to good yields through a cyclo
- Chen, Kai,Jiang, Min,Zhang, Zhen,Wei, Yin,Shi, Min
-
p. 7189 - 7193
(2012/01/19)
-
- 63. Enantioselective Formation of Bicyclic Lactones by Rhodium-Catalyzed Intramolecular CH-Insertion Reactions
-
The decomposition of cyclohexyl diazoacetate (5a) in the presence of the chiral 4> catalyst leads to a 3:1 cis/trans mixture of bicyclic lactone 6a with an enantiomeric excess of 95-97percent (cis) and 90percent (trans).The conformationally rigid tert-butyl derivatives 5b and 5c afford, in the presence of the same catalyst, 6b and 6c, respectively, via insertion into the equatorial C-H bonds exclusively, with ee's of ca. 95percent.A remarkable degree of induction (92-95percent) results in the lactone 6g upon decomposition of 1-isopropyl-2-methylpropyl diazoacetate (5g).The diazoacetates derived from 1-methylcyclohexanol, cyclopentanol and 1-methylcyclopentanol (5d-f) afford under similar conditions insertion products with higher diastereoselectivity, but significantly lower enantioselectivity.Other dirhodium catalysts are less efficient.
- Mueller, Paul,Polleux, Philippe
-
p. 645 - 654
(2007/10/02)
-
- A Radical Cyclisation Strategy to α-Spiro-β-methylene-γ-butyrolactones. Total Synthesis of (+/-)-Norbakkenolide-A
-
The 5-exo-dig radical cyclisation reaction of the bromoacetals 9, obtained from the enol ethers 8, and treatment of the resulting hemiacetal 10 with Jones' reagent transforms the cyclic ketones 7 and 12 into α-spiro-β-methylene-γ-butyrolactones 11 and norbakkenolide-A 2.
- Srikrishna, Adusumilli,Nagaraju, Sankuratri,Sharma, G. Veera Raghava
-
p. 285 - 288
(2007/10/02)
-
- Formation of trans Ring-Fused Compounds by an Alkylation-Radical Cyclization Sequence
-
Enolates derived from bicyclic lactones of type 1 (Scheme I) can be alkylated with 2-propynylic halides to give products 2, in which the unsaturated alkyl group is syn to the adjacent ring-fusion hydrogen.Reaction of 2 with sodium phenyl selenide and then
- Clive, Derrick L. J.,Manning, Hartford W.,Boivin, Taryn L. B.,Postema, Maarten H. D.
-
p. 6857 - 6873
(2007/10/02)
-
- Construction of trans-Ring-fused Compounds by Radical Cyclization
-
Enolates derived from bicyclic lactones of type (4) are alkylated with prop-2-ynylic (and allylic) bromides to give products (5) in which the unsaturated alkyl group is syn to the remaining ring-fusion hydrogen; prop-2-ynylic aldehydes can be used instead
- Clive, Derrick L. J.,Manning, Hartford W.,Boivin, Taryn L. B.
-
p. 972 - 974
(2007/10/02)
-