About the timing of Wagner-Meerwein and Nametkin rearrangements, 6,2-hydride shift, proton elimination and cation trapping in 2-norbornyl carbocations
作者:Antonio García Martínez、Enrique Teso Vilar、Amelia García Fraile、Antonio Herrera Fernández、Santiago de la Moya Cerero、Florencio Moreno Jiménez
DOI:10.1016/s0040-4020(98)00176-8
日期:1998.4
The reaction of different substituted 2-norbornanones 1 with triflic anhydride in the presence of nitriles 6 is carried out in order to study the factors that influence on the different reaction possibilities of 2-norbornyl carbocations. The syntheses of interesting annulated pyrimidine derivatives 10 and conformationally rigid 1,3 disubstituted products are described.
2-dimethyl-3-oxotrifluoromethylsulfonyloxynorbornane [(−)-8] in 60% ethanol takes place with cleavage of C-2/C-3 bond to afford a mixture of (−)-(IR)-3-(1-methylethylidene)cyclopentane car☐ylicacid (−)-(1c) (56%) and its corresponding ethylester (−)-1d (21%).
Synthesis of homochiral 1,2-diols from (−)-fenchone and (+)-camphor
作者:A. García Martïnez、E. Teso Vilar、A.Garda Fraile、S. de la Moya Cerero、L.R. Subramanian
DOI:10.1016/0957-4166(94)80180-0
日期:1994.7
(+)-(1R,2S)-1,2-dihydroxy-7,7-dimethylnorbornane (3) and (−)-(1R,2R)-1,2-dihydroxy-3,3-dimethylnorbornane (12) have been obtained from (−)-fenchone and (+)-camphor.
Unusual reactivity of norbornane bridgehead derivatives
作者:A. García Martínez、E. Teso Vilar、A. García Fraile、J. Osío Barcina、M. Hanack、L.R. Subramanian
DOI:10.1016/s0040-4039(00)99502-9
日期:1989.1
The solvolysis of 2,2,3- and 2,3,3-trimethyl substituted 1-norbornyl triflates 1 and 6 in 60% aqueous ethanol at 60°C proceeds via novel σ-bridged carbocations affording products mainly from hitherto unknown Wagner-Meerwein rearrangement and fragmentation reactions, respectively.