The Synthesis of 6-Hydroxy-1,3,4,5-tetrahydrobenz [cd] indole¹

Facile interconversion of the isomeric acid chlorides derived from half methyl esters of 3-methoxyphthalic acid

“…The combined filtrate and washings were washed with ether (3 x 150 ml) and then acidified to pH 1; the resulting precipitate was extracted with dichloromethane (3 x 100 ml). The combined extracts were washed with water (200 ml), dried, and evaporated to dryness to afford the title compound (11) The acid (1) (1.00 g) was stirred under nitrogen with freshly distilled thionyl chloride (5 ml) at 20 "C. After 2 h carbon tetrachloride (20 ml) was added and the mixture reduced in volume to ca. 5 ml using a rotary evaporator operating at 10 mmHg and a water-bath at 20 "C. The addition and evaporation of solvent was repeated twice.…”

Mimicking the Reaction of Phenylalanine Ammonia Lyase by a Synthetic Model

“…The corresponding alcohol 18 was obtained by reduction with LiAlH 4 [32] and then converted via mesylate 19 to nitrile 20 [33]. The a-acidifying effect of the nitrile group was exploited to substitute one of the methylene protons by the acetal-protected 3-bromopropanal, thus generating intermediate 21 [34]. Reduction by LiAlH 4 resulted in amine 22, which was dimethylated by CH 2 O/NaCNBH 3 [35] [36].…”

Total Syntheses of (±)-Preussomerins G and I

“…Our synthesis of the preussomerins begins with the known 5,8-dimethoxytetralone ( 9 ), which is converted into the corresponding methyl enol ether 10 , which was allowed to react with 4-acetoxy-1,8-naphthalenediol 7 to obtain the requisite monoacetal 11 . Hydrolysis of 11 with sodium methoxide in methanol yielded hydroxymonoacetal 12 (Scheme 1).…”