Synthesis of the Benzophenone Fragment of Balanol via an Intramolecular Cyclization Event

Abstract

Studies are reported on the use of either a 7-exo radical cyclization or an intramolecular Heck reaction as the key step for the construction of the benzophenone fragment of the PKC inhibitor, balanol. Whereas, the former approach was unsuccessful, the Heck reaction proved to be viable for the coupling of two fully functionalized aryl subunits affording regioselectively a biaryl seven-membered lactone with an exocyclic alkene as the major component, in contrast to the competing eight-membered ring lactone. Hydrolysis of the lactone followed by oxidative cleavage of the alkene with ruthenium tetraoxide completed this short synthesis of the benzophenone unit.

Synthesis and phase behavior of dendrons derived from 3,4,5-tris(tetradecyloxy)benzoic acid with different functional groups in focal point

“…The benzyl ester of 3,5-dihydroxybenzoic acid, employed as a protecting block in the esterification, was prepared by means of alkylation of the carboxyl group of 3,5-dihydroxybenzoic acid with benzyl bromide in dry DMF. 25 The hydroxyl groups location in the structure of the benzyl ester of 3,5dihydroxybenzoic acid are sterically favorable for further molecular growth. The protecting group is easily introduced into the molecule, and selectively removed without any alterations in the structure of the formed compound.…”

Synthesis of Wholly Aromatic Polyketones

“…There have been reported various approaches for homo aryl coupling and cross aryl coupling. Intramolecular 63,64 or intermolecular aromatic ring formation [65][66][67][68][69][70] is a plausible protocol for this polymer synthesis. Functional group interconversion of a substituent attached to the main chain of the precursor polymer to carbonyl group is also one of the possible approaches.…”

Novel stationary phase for complexation gas chromatography originating from ionic liquid and metallomesogen

“…Herein, we present the detailed and modified procedures used in the present synthesis. The preparation of 3,4,5-tridodecyloxybenzoic acid (4) was started with the esterification of 3,4,5-trihydroxybenzoic acid 6) was converted to its benzyl ester with benzyl bromide in DMF at room temperature, affording benzyl-3,5-dihydroxy benzoate (7) [51] with a yield of 74%. The esterification of the compound 7 with 3,4,5tridodecyloxybenzoylchloride (5) which was freshly prepared by refluxing the compound 4 in an excess of thionyl chloride, in the presence of triethylamine in dichloromethane at room temperature gave benzyl-3,5-bis(3,4,5-tridodecyloxybenzoyloxy)benzoate ( 8) with a yield of 64%.…”