Cyclisation of 5-bromomethyl-cycloheptene and -cyclo-octene: a new route to bicyclo[3.2.1]octanes and bicyclo[4.2.1]nonanes
作者:Finlay MacCorquodale、John C. Walton
DOI:10.1039/p19890000347
日期:——
of 5-(bromomethyl)cycloheptene with tributyltin hydride gave bicyclo[3.2.1]octane; similar reduction of 5-(bromomethyl)cyclo-octene gave bicyclo[4.2.1]nonane together with some bicyclo[3.3.1]nonane. The cyclohept-4-enylmethyl radical intermediate exists as a rapidly equilibrating mixture of conformers, including the axial boat form from which cyclisation occurs. The rates of the two main cyclisation
用氢化三丁基锡还原5-(溴甲基)环庚烯,得到双环[3.2.1]辛烷; [M + H] +。5-(溴甲基)环辛烯的类似还原得到双环[4.2.1]壬烷和一些双环[3.3.1]壬烷。环庚-4-烯基甲基自由基中间体以构型的快速平衡混合物形式存在,包括发生环化作用的轴向舟形。两个主要环化反应的速率约为 在25°C下10 5 s –1。将4-甲基环己酮的二甲基胺烯胺与丙烯醛缩合,随后用甲基碘和碱处理,得到6-甲基八氢-1-苯并吡喃-2-酮。
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
Formation of bicyclo[3.2.1]octane, bicyclo[4.2.1]nonane, and bicyclo[3.3.1]nonane by transannular radical cyclisations
作者:Finlay MacCorquodale、John C. Walton
DOI:10.1039/c39870001456
日期:——
Cyclohept-4-enylmethyl radicals undergo transannular cyclisation to give bicyclo[3.2.1]octane; likewise, bicyclo[4.2.1]nonane and bicyclo[3.3.1]nonane are obtained from cyclo-oct-4-enylmethyl radicals.