The Methyl Esters of 3-Hydroxyphthalic Acid. Selective Reduction of Monomethyl Phthalates with Lithium Aluminum Hydride

Synthesis and Activity of Substituted Anthraquinones against a Human Filarial Parasite, Brugia malayi

“…3-Hydroxyphthalic anhydride is very expensive and its preparation by reacting maleic anhydride with 2-triethylsiloxyfuran followed by the aromatization of the resulting cyclic adduct was reported. 20 It was also prepared by using 3-aminophthalic anhydride 21 or 3,6diiodophthalic anhydride 22 as synthons. However, all of these published methods resulted in very poor yields.…”

Series nucleophilic catalysis in the hydrolysis of 3-acetoxyphthalate. Intramolecular catalysis of ester hydrolysis by the carboxyl group once removed

“…Since the hydrolysis products are a mixture of three ionic species for hydroxide Apparent pXVs 25 M"1 min"1 3.11 ± 0.03, 4.6 ± 0.V <* HC1 solution. 6 Formate buffer (0.05 M). Buffer catalysis is insignificant compared with changes in rate due to small pH changes caused by varying buffer concentration. '…”

“…(10) We have not investigated this phenomenon. The phenolic group of the 3-hydroxyanhydride has a pA"a near [6][7] (see above) and it is possible that the phenolate oxygen of one molecule attacks the anhydride group of another, to form eventually an eight-membered bislactone, which is being hydrolyzed in the second, slower, step to 3-hydroxyphthalate. We are satisfied that the known reactivities of phenolate anions make this quantitatively possible, but have no relevant evidence.…”

Recent advancements in synthetic methodologies of 3-substituted phthalides and their application in the total synthesis of biologically active natural products

“…14 Later in 1955, Eliel and coworkers performed the reduction of methyl phthalate to phthalide in good yield using LiAlH 4 . 15 In 1989, Watanabe and coworkers utilized a Diels-Alder reaction between substituted furanones and silyloxydienes to provide substituted phthalides in moderate to excellent yields. 16 Recently, directed ortho-metallation, the reaction between homophthalic anhydride and benzil, 17 the Heck-Matsuda reaction, 18 and many more methods have been introduced to synthesize substituted phthalides.…”