Unambiguous Proof for Alcoxycarbonyl-group Migration inWagner-Meerwein Rearrangements
作者:Daniel Berner、Hans Dahn、Pierre Vogel
DOI:10.1002/hlca.19800630849
日期:1980.12.10
HSO3F/SO2ClF the β-hydroxy esters Ph-CHOH-CMe2-COOR (1, RMe, Et) are doubly protonated, then transformed into the fluorosulfates 7 and (partly) into the fluorides 8. At −15°, both 7 and 8 undergo a rearrangement, forming derivatives of Me2CC(Ph)COOR (2). By labelling 1 with 13C, singly (13C(3)) and doubly (13C(1,3)), it could be shown that exclusively the ROOC groups undergo a 1,2-shift. Compound 2 is also
在HSO 3 F / SO 2 ClF中,将β-羟基酯Ph-CHOH-CMe 2 -COOR(1,RMe,Et)进行双质子化,然后转化为氟代硫酸盐7和(部分)转化为氟化物8。在-15 °,7和8均发生重排,形成Me 2 CC(Ph)COOR(2)的导数。通过标记1与13 C,单独使用(13 C(3))和双(13 C(1,3)),则可以示出专门的ROOC基团经历1,2-移。化合物2也在HSO 3 F / SO中形成通过消除,从异构体Me 2 COH-CHPh-COOR(3)中除去2 ClF ,并且不容易通过苯基1,2-移位从α-羟基酯Ph-CMe 2 -CHOH-COOR (5)中除去2 ClF 。另一个异构体Ph-C(OH)Me-CHMe-COOR (4)得到的产品与2不同。