[EN] TROPOLONE DERIVATIVES AND TAUTOMERS THEREOF FOR IRON REGULATION IN ANIMALS [FR] DÉRIVÉS DE TROPOLONE ET LEURS TAUTOMÈRES POUR LA RÉGULATION DU FER CHEZ LES ANIMAUX
[EN] TROPOLONE DERIVATIVES AND TAUTOMERS THEREOF FOR IRON REGULATION IN ANIMALS [FR] DÉRIVÉS DE TROPOLONE ET LEURS TAUTOMÈRES POUR LA RÉGULATION DU FER CHEZ LES ANIMAUX
The directed zincation of tropolone derivatives was achieved using TMPZnCl·LiCl. Various functionalizations of the zincated intermediates by halogenation, acylation, allylation, and Negishicross-coupling were successfully performed. Additionally, 1,8-conjugate addition–elimination reactions with a variety of arylmagnesium and secondary alkylzinc reagents were carried out to further elaborate the tropolone
The kinetic features of the [1,9] sigmatropy (with 2-benzyloxy-3-bromotropone) and the [3,3] sigmatropy (with 2-allyloxytropone and 2-[(3-methyl-2-butenyl)oxy]tropone) were investigated under various pressures (1 to 1600 bar). The activation volume of [1,9] sigmatropy was of the same order as those of [1,5] sigmatropy of cyclopentadienes. The activation volume of [3,3] sigmatropy of more sterically-hindered
High-pressure Kinetic Analysis of [1,9] Sigmatropy of 2-(Benzyloxy)-3-bromotropone to 2-(Benzyloxy)-7-bromotropone
作者:Shigeru Sugiyama、Akira Mori、Hitoshi Takeshita
DOI:10.1246/cl.1987.1247
日期:1987.7.5
Thermal rearrangement of 2-(benzyloxy)-3-bromotropone to 2-(benzyloxy)-7-bromotropone, regarded to be the first [1,9] sigmatropic rearrangement, was analyzed by high-pressure kinetics. ΔV≠ for the process were shown to be −11.1 and −10.1 cm3 mol−1 in isopropylbenzene and 1-hexanol, respectively. The figures confirmed the concerted nature of the rearrangement, and were similar to various [1,5] sigmatropies of cyclopentadienes.