The Synthesis of Strained Methylene-bridged Bicyclic Olefins by the IntramolecularWittig Reaction
作者:Konrad B. Becker
DOI:10.1002/hlca.19770600111
日期:1977.1.26
A convenient synthesis of the strained methylene-bridged trans-cyclooctenes bicyclo[3.3.1]-1 (2)-nonene (1), bicyclo[4.2.1]-1(8)-nonene (2), and bicyclo[4.2.1]-1(2)-nonene (3) by the intramolecular Wittig reaction is described (see Schemes 1–4). The (3-oxocycloalkyl)alkyl-phosphonium bromides 20, 27 and 38 undergoing cyclization to the bridgehead olefins are formed by simple reaction sequences. The
[2 + 2]-Cycloadditions to Strained Bridgehead Olefins. II. Diphenylketene
作者:Konrad B. Becker、Martin K. Hohermuth、Grety Rihs
DOI:10.1002/hlca.19820650122
日期:1982.2.3
The strained bridgehead olefins bicyclo [3.3.1]non-1-ene (1), bicyclo [4.2.1 ]non-1(8)-ene (2), and bicyclo [4.2.1]non-1-ene (3), and the comparable monocyclic (E)-1-methylcyclooctene (4) react with diphenylketene (6) to give a single cycloadduct 7, 8, 9 and 10, respectively, in which the diphenyl-substituted C-atom is bound to the bridgehead. The structure of the cyclobutanone 8 has been determined
[2 + 2]-Cycloadditions to Strained Bridgehead Olefins. I. 1, 1-Dichloro-2,2-difluoroethene
作者:Konrad B. Becker、Martin K. Hohermuth
DOI:10.1002/hlca.19820650121
日期:1982.2.3
The strained bridgehead olefins bicyclo [3.3.1]non-1-ene (1), bicyclo [4.2.1] non--1-(8) (2), and bicyclo [4.2.1]non-1-ene (3) react rapidly with 1,1-dichloro-2, 2--difluoroethene (5) to yield mixtures of regioisomeric dichlorodifluorocyclobutanes 8/9, 10/11 and 12/13, respectively. On the contrary, the reaction of 5 with the model compound (E)-l-methylcyclooctene (4) is completely regioselective.