Synthesis of Taiwaniaquinoids via Nazarov Triflation
摘要:
A unified approach toward the taiwaniaquinoids that has yielded four natural products is described. A new variant of the Nazarov reaction with concomitant formation of an enol triflate serves as one of the key steps, considerably shortening the synthetic scheme and providing a general entry into this class of bioactive natural products.
Metal triflate-catalyzed cyclization of arylvinylcarbinols: formal synthesis of (±)-dichroanone and (±)-taiwaniaquinone H
作者:Badrinath N. Kakde、Subhadip De、Dhananjay Dey、Alakesh Bisai
DOI:10.1039/c3ra41497c
日期:——
A formal synthesis of diterpenoids viz. the taiwaniaquinoids (±)-dichroanone (1a) and (±)-taiwaniaquinone H (1b) possessing an all carbon quaternary stereocenter has been reported. The key step involves a metal triflate-catalyzed cyclization of arylvinylcarbinols, prepared from β-cyclocitral. The reaction possibly follows a stepwise mechanism via the intermediacy of arylallyl carbocationic species
A very expedient and efficient new route toward taiwaniaquinoids, bearing the 4a-methyltetrahydrofluorene skeleton, is reported. Key steps are the intramolecular Friedel−Crafts alkylation of an aryldiene and the degradative oxidation of a methylenedioxy group; the latter process could also be utilized for building the 2-hydroxy-1,4-benzoquinone unit, which is frequently found in natural products. Utilizing
Design and synthesis of guanidine-containing novel retinoids
作者:Bhaskar C. Das、Sakkarapalayam M. Mahalingam、Pranoy Mohapatra
DOI:10.1016/j.tetlet.2009.08.008
日期:2009.10
Guanidine-containing new retinoids 1-4 were synthesized through the addition of guanidine to the activated carboxylic acids (retinoids) promoted by carbonyldiimidazole (CDI). A set of structurally and functionally diverse guanidine derivatives of retinoids were obtained in high yields (78-82%). We are in the process of studying the biological effect of these molecules on retinoic acid signaling pathways. (C) 2009 Elsevier Ltd. All rights reserved.
[EN] OPSIN-BINDING LIGANDS, COMPOSITIONS AND METHODS OF USE<br/>[FR] LIGANDS SE LIANT AUX OPSINES, COMPOSITIONS, ET PROCÉDÉS D'UTILISATION
申请人:BIKAM PHARMACEUTICALS INC
公开号:WO2011155983A1
公开(公告)日:2011-12-15
Compounds are disclosed that are useful for treating ophthalmic conditions related to mislocalization of opsin proteins, the misfolding of mutant opsin proteins and the production of toxic visual cycle products that accumulate in the eye. Compositions of these compounds, either alone or in combination with other therapeutic agents, are also disclosed, along with thereapeutic methods of using such compositions. Methods of synthesizing such compounds are also described.
[EN] OPSIN-BINDING LIGANDS, COMPOSITIONS AND METHODS OF USE<br/>[FR] LIGANDS LIANT L'OPSINE, COMPOSITIONS ET PROCÉDÉS D'UTILISATION
申请人:BIKAM PHARMACEUTICALS INC
公开号:WO2012134971A2
公开(公告)日:2012-10-04
Compounds and compositions of said compounds along with methods of use of compounds are disclosed for treating ophthalmic conditions related to mislocalization of opsin proteins, the misfolding of mutant opsin proteins and the production of toxic visual cycle products that accumulate in the eye. Compounds and compositions useful in the these methods, either alone or in combination with other therapeutic agents, are also described, along with methods of use.