The reaction between copper (I) methyltrialkylborates readily obtainable from organoboranes and 1-(-1-pyrrolidinyl)-6-chloro-1-cyclohexene was found to give corresponding alkylation products which are readily hydrolyzed to alkylated cyclohexanones.
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.
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.
polycyclic unsaturated alcohols of type A to ethers D (Scheme 1). The alkoxide anion B is formed first in a fast acid-base equilibrium. For the subsequent reaction to D, a carbanion-like transition state C is proposed. This mechanism is in full agreement with our results regarding the influence of substituents on the regioselectivity and the rate of cyclization. We studied the effect of alkyl substituents
提出了一种机理模型,用于将 A 型多环不饱和醇碱催化分子内环化为醚 D(方案 1)。醇盐阴离子 B 首先在快速酸碱平衡中形成。对于随后对 D 的反应,提出了类碳负离子过渡态 C。这种机制与我们关于取代基对区域选择性和环化速率影响的结果完全一致。我们研究了烷基取代基在烯丙基位置(烷基化的内环烯醇 1-3),特别是在环外双键(12-15)上的影响。最快的环化 (krel=1) 是 1216,它通过初级碳负离子状过渡态 (E: R1=R2=H) 进行。相应的过程 1317 和 1417 的特点是不稳定的次生碳负离子过渡态 (E:
[4 + 3] Cycloadditions of cyclic oxyallyls and cyclic 1,3-dienes.
作者:Shu-juan Jin、Jong-Ryoo Choi、Jonghoon Oh、Dongha Lee、Jin Kun Cha
DOI:10.1021/ja00149a014
日期:1995.11
The [4 + 3] cycloaddition of the oxyallyl intermediates, derived from 2-chlorocyclohexanone and related compounds, to cyclic 1,3-dienes under the Fohlisch conditions (Et(3)N in CF3CH2OH) has been examined to assess its scope and limitations. Effects of substitution with alkyl or alkoxy groups on the cyclohexanone ring, along with variations of the base, solvent, or ring size have been investigated. Also included is a comparison between the Fohlisch cycloaddition and the Schmid cycloaddition (utilizing alpha'-chloroenamines). These reactions of cyclic oxyallyls afford tricyclic or tetracyclic cycloadducts of considerable molecular complexity with a well-defined stereochemical outcome and, thus, represent a new synthetic route to functionalized medium-sized carbocycles and heterocycles.