[13]瓦格聂尔(Wagner,A,BarHep,E.E.)重排(即瓦格聂尔-米文Wagner-Meerwein重排)①瓦格聂尔(俄国)首先在研究醇在Lewis酸存下,在消除(脱水)取代反应中发生碳胳变化而形成获烯的重排反应。米文(德国)在研究其它类型的有机化合物时发现类似的重排。费脱玛(W.Whitmore)提出了有关正碳离子的重排历程。实例和反应历程1.新戊醇和HOI反应时发生的重排反应:CH3CH3HCI-H.0CH3-C-CH2OHC-CH,OH,OHdHsCH3亲核重排不稳定的伯正碳离子-H+CHg—CCHCH:(消除重排产物)CH30-OH,CH3CH3C1CHs+Cl-CHCH2OH:(取代重排产物)稳定的权正碳离子CH3实际上OH的离开和CH的迁移是协同进行的,碳胳发生了变化:CC00000d其他类似化合物会发生同样的反应:.35:
CHsNaNOa/HCICH.-O--OH,NH,-N2CH:dHs重排OH,→OH--0-CHsCHsAgtCH-O--OH,IAglOH?-H+CHa--O--CHOH3OHsCH.-OH,OH3NuOHstNu.OHg-O-CHOHsOH2.3,3-二甲基-丁醇-2在无水草酸存在下100~110℃加热时发生脱水重排反应(主要生成Syn-四甲基乙烯)②:HC HH.C HHO HH+-H0OH.--OO--CH→OH3-C-C-H3>CH.--0-0OH,H0(OHH.0OH,H.0+仲正碳离子H+OH:OH3C-OH--CH,CHs3%(正常脱水产物)重排HCHCH3H+61%CH.CH.CHOH?重排产物H+CH2-C-OH(OH3)2 31%H.COH3叔正碳离子OHs.36:
碳胳的变化和片呐醇重排相反,因此瓦格聂尔一米文重排属于反片呐醇重排(RetropinacolRearrangement):CO瓦-米重排C-000片呐醇重排03.氯(Bornyl-chloride)在特殊情况下脱去氮化氢时*,生成烯(Oamphene)?:OH,CH:C01HC.OHH,0OHΦ-OK,180℃(或单独加热)-C--CH3CH3CH3-CH3-HCIH,CCH.H,CCH?OHC(烯)(1)罗瑞契卡(Ruzicka)历程?:*氯在另外一种情况下脱HCl,可避免发生重排反应,生成纯粹的烯-[2](Bornylene):CH3CH3CH,CCHHHO.H10Na(10%)CH:CH-CH3CH,230~2400-HCIOHCH2H2CHC.37
CH:CHsCHCHOI-OHHC[H-OH-HCI(烯)CH3CH3CH3CH3(重排)CHaCH2H,CH,COH-OH不安定中间物(Tricyclene)(2)英果(Ingold)历程④HCH:-CHC1COHH,0H,OOHOIHCI(重排)烯CH3-CH3CH3-CH3OHH,COHaHC(3)费脱玛②正碳离子历程:CH3CHalHCHCHH-CICH3--CH3CH-C-CH3CHCH2H,CCH2OH2CH3COOHH,CH,CHH-H+重排CH3CH3CH3--C-CH?HCH,0CH2CH·38:
4.醇(樟脑醇,Borneol)或异获醇(isoBorneol)用H,SO4,P.Os或ZnOla等脱水剂脱水时,起重排反应生成获烯。OH3HH.COHCH,CH,-O-CHOCH?H,OHO-OHOHH20(醇)CH3C--CH3(重排)OH3H,0OH,.OHH.OHCH:C-CHCHaH,o(异醇)费脱玛(Whitmore)历程:②,?CHsCECHOHOHCH2CH-H.0+H+CHg-C-CH3CH3--C—CH3CH,CH,H,0OHaCH3CHsotOHH20CH,CH-H+烯CH3--C-CH3CH3-C-CH,CH,CHCHH20:39: