The Effect of Base and Nucleophile on the Nucleophilic Substitution of Methoxytropone Derivatives: An Easy Access to 4- and 5-Substituted Multifunctional Azulenes
作者:Neha R. Kumar、Abhijeet R. Agrawal、Aditya Choudhury、Sanjio S. Zade
DOI:10.1021/acs.joc.0c00951
日期:2020.7.17
nucleophilic substitution on 3-substituted 2-methoxytropones to form azulenes is dependent on the nucleophile and base employed. With bulkier nucleophiles (ethyl/methyl cyanoacetate), the reaction proceeds with the abnormal nucleophilic substitution irrespective of the base and with smaller nucleophiles (malononitrile), the reaction follows base-dependent normal and abnormal nucleophilic substitution. Thus
An anti-mycoplasma agent comprising tropolone, its derivatives, represented by the formula: ##STR1## (wherein R.sub.1 is hydroxy, aliphatic acyloxy, arylacyloxy, arysulfonyloxy, carboxyalkyloxy or its ester, benzoylalkyloxy, alkenyloxy, 1,3-dihydro-3-oxo-1-isobenzofuranyloxy, (2-oxo-5-methyl-1,3-dioxol-4-yl)methyloxy or thiocyanato and R.sub.2 is hydrogen, halogen, hydroxy, alkyl or alkoxy) and their salts as an active ingredient, which has potent activity especially against tylosin-resistant mycoplasma both in vitro and in vivo and is effectively used in treating the diseases caused thereby.
Synthesis and biological evaluation of O-alkylated tropolones and related α-ketohydroxy derivatives as ribonucleotide reductase inhibitors
作者:I Tamburlin-Thumin
DOI:10.1016/s0223-5234(01)01249-1
日期:2001.6
A series of O-alkylated tropolones and related alpha-ketohydroxy compounds were evaluated for their biological activities and were shown to present an expected ribonucleotide reductase inhibition and cytotoxicity against some cancer cell lines but no antitubulin activity. Pharmacomodulation studies were realised to understand and enhance the observed activities. These original benzylic, heterocyclic
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