Reactions of Quino‐Ketenes with C‐Nucleophiles: Syntheses of (2‐Hydroxyphenyl)methanols and 2‐Hydroxyphenyl Ketones

Abstract

In this study, we have developed a new, efficient, and one‐step protocol for the synthesis of derivatives of 2,4‐dihydroxyphenyl ketones and/or 2,4‐dihydroxyphenyl/naphthalenyl methanols starting from benzodioxinones/naphthodioxinones and organolithium compounds. Reactions have been performed under thermal conditions without catalyst. This work is the first example of the preparation of these products starting from 2‐hydroxy acids.

Preparation of Salicyl Alcohols and 9‐Arylxanthenes Using Sodium Salicylates and Bromo‐Hydrocarbons Mediated by PPh3

“…Conventionally, salicyl alcohols could be synthesized utilizing excess or even much excess Grignard reagents to react with salicylic acid . Furthermore, organolithium reagents were also added to protected salicylic acid, methyl salicylate, or 2‐hydroxy aromatic ketone to give salicyl alcohols. In these works, organolithium of o ‐bromophenol required 2.0 equiv.…”

Discovery and Structural Optimization of Acridones as Broad-Spectrum Antimalarials

“…The acridones 98 and 99 , which contain a F atom at the 2 position and OMe group at the 3 position of ring-A, and (diethylamino)ethoxy and (diethylamino)ethyl-amino groups at the 6 position of the ring-B, were synthesized from the methyl 2,4-dihydroxybenzoate ( 56 ) and methyl 4-iodosalicylate ( 94 ), respectively. Coupling of 56 with 2-bromo- N,N -diethylethylamine in the presence of tetrabutylammonium chloride (TBAC) 27 and K 2 CO 3 provided compound 95a . Coupling of 94 with 2-diethylaminoethylamine in the presence of CuI/Cs 2 CO 3 28 and 2-acetylcyclohexanone provided 95b .…”

Nucleophilic Addition Reaction with Dearomatization of Naphthalene Ring

“…The mixture was extracted with ethyl acetate, washed with brine, dried over sodium sulfate, concentrated and purified by chromatography (SiO 2 , hexane : ethyl acetate) to give 1,2-adduct 9 and mixture of 1,2-adduct 10 and 1,4-adduct 11. Then the mixture was again purified by chromatography (SiO 2 -NH, hexane : ethyl acetate) to give corresponding 1,2-adducts 10 and 1,4-adducts 11.Compound 9a: Known 21…”