The alleged isolable 1,4,5,6-tetrachloro-7,7-dimethoxynorbornadiene-2,3-dicarboxylic anhydride
摘要:
Addition of dibromomaleic anhydride to tetrachlorocyclopentadienone dimethyl acetal gives the pseudo-lactone 11 (X-ray crystal structure analysis) and not the mixture of endo- and exo-adducts 2 previously claimed; reduction of this product with Zn/HOAc gives 13 and 14 rather than the putative isolable norbornadienone acetal 3.
The role of norcaradiene intermediates in the rearrangement of norbornadien-7-one acetals
作者:Dionis E. Sunko、Zdravko Lovrić、Hrvoj Vančik
DOI:10.1039/c39850001589
日期:——
The bis(methoxycarbonyl)tetrachlorobornadienone dimethyl acetal (1) rearranges spontaneously to the hemimellite (2)via the norcaradieneintermediate (6); the corresponding anhydride (5) is stable below 200 °C because steric strain prevents its conversion into a analogous into an analogous intermediate (9).