A concise, simple two-step method for the preparation of [4+3] cycloadducts from ketones using Koser"s reagent and trifluoroethanol-triethylamine has been developed. This sequence affords yields similar to those obtained using the α-halo and α-mesyloxyketones, but with the advantages of simplicity in preparation and stability of the intermediates.
Nucleophilic Addition to C, C-Double Bonds. IV. Ether formation by intramolecular addition to unsymmetrically alkyl-substituted C, C-double bonds
作者:Gerardo M. Ramos Tombo、Rolland A. Pfund、Camille Ganter
DOI:10.1002/hlca.19810640320
日期:1981.4.29
Tricyclic olefinic alcohols containing an unsymmetrically alkyl-substituted C, C-double bond were cyclized intramolecularly to their corresponding ethers under basic conditions: 9 12, 10 17 + 18, and 11 12(Scheme 3, Table 1). The reactivity is mainly due to relieve of ground state strain.
Syntheses and PE-Spectroscopic Investigations of 2,6- and 3,5-Bridged 1,4-Dimethylidenecyclohexanes
作者:Teh-Chang Chou、Holger Lange、Rolf Gleiter、Tibor Gögh、Miroslav Kríž、Max H. Pfenninger、Marian Valentíny、Camille Ganter
DOI:10.1002/hlca.19950780809
日期:1995.12.13
Three 1,4-dimethylidenecyclohexanes, bridged in the 2,6- and 3,5-positions by two ethano (4), one ethano and one propano (5), and two propano bridges (6) have been synthesized. The interaction of the two exocyclic methylidene groups has been investigated by He(I) photoelectron (PE) spectroscopy. It revealed a slightly larger energy difference (0.8 eV) for 4 and 5 as compared to the parent 1,4-dime
Silberioneninduzierte Reaktion von 3-Chlor-2-pyrrolidinocyclohexen mit 1,3-Dienen. Vorläufige Mitteilung
作者:Rudolf Schmid、Hans Schmid
DOI:10.1002/hlca.19740570642
日期:——
3-Chloro-2-pyrrolidinocyclohexene (3) in the presence of silver tetrafluoroborate in methylene chloride at −60° underwent cycloadditions with various 1,3-dienes; the resulting iminium tetrafluoroborate salts 4a–8a were hydrolysed to give the bicyclic and tricyclic ketones 4b–8b. The addition reactions can be regarded as [3+4]-cycloadditions of an intermediate 2-aminoallyl cation.
Nucleophilic addition to C, C-double bonds. VI. Intramolecular addition of primary amines to C, C-double bonds induced by steric compression
作者:Gerardo M. Ramos Tombo、Camille Ganter
DOI:10.1002/hlca.19820650738
日期:1982.11.3
The tricyclic olefinic primary amine 1 readily cyclizes to the tetracyclic secondary amine 2 at approximately 200° in protic as well as aprotic solvents although the C, C-double bond is not activated by electron-attracting groups. This unusual intramolecular addition is the consequence of the close proximity of the nucleophile and the double bond.