Coumarins. VII. The Acid-catalyzed Reaction of Aromatic Compounds with β-Chlorocarboxylic Acids

Abstract

The aluminum chloride-catalyzed reaction of aromatic compounds, such as benzene and phenols, with β-chlorocarboxylic acids was investigated. Although the reactions of benzene, toluene, and chlorobenzene with β-chloropropionic acid were found to give the corresponding dihydrocinnamic acids in high yields, attempts to prepare dihydrocoumarin by a similar reaction of phenol were unsuccessful. Similarly, β-arylbutyric acids were obtained in good yields by means of the aluminum chloride-induced reaction of aromatic hydrocarbons with β-chlorobutyric acid (Ib). In contrast, phenols, such as phenol, o- and m-cresols, reacted with Ib under similar conditions to provide the corresponding β-(p-hydroxyphenyl)butyric acids in 22–60% yields, while a 51% yield of β-(5-hydroxy-2-methylphenyl) butyric acid was obtained upon a similar treatment of p-cresol with the acid Ib.

Enantioselective Hydrogenation of β,β-Disubstituted Unsaturated Carboxylic Acids under Base-Free Conditions

“…Data for (S)-3-phenylbutanoic acid (2a): light yellow liquid; yield 20.1 mg, 98%; 97% ee; 38 Data for (+)-3-(o-tolyl)butanoic acid (2j): light yellow solid; yield 21.8 mg, 98%; 99.3% ee; [α] D 20 = +16.2 (c = 1.11, CH 2 Cl 2 ) [lit. 13 [α] D 20 = +8.8 (c = 1.00 CHCl 3 ) for 16% ee]; HPLC (Lux 5u Cellulose-1 (250 × 4.60 mm), ipa:hex = 10:90, 1 mL/min, 254 nm) t R = 21.0 min (major), t R = 22.9 min (minor); 1 H NMR (400 MHz, CDCl 3 ) δ = 9.52 (s, 1H), 7.21−7.117 (m, 4H), 3.60−3.51 (m, 1H), 2.73−2.55 (m, 2H), 2.39 (s, 3H), 1.30 (d, J = 6.9 Hz, 3H); 13…”

“…light yellow liquid; yield 24.3 mg, 98%; 93% ee; [α] D 20 = −16.4 ( c = 1.22, CH 2 Cl 2 ); HPLC (Lux 5u Cellulose-1 (250 × 4.60 mm), ipa:hex = 20:80, 1 mL/min, 254 nm) t R = 10.1 min (major), t R = 11.6 min (minor); 1 H NMR (400 MHz, CDCl 3 ) δ = 7.38–7.27 (m, 1H), 7.25–7.22 (m, 2H), 7.18–7.14 (m, 1H), 3.85–3.76 (m, 1H), 2.79–2.53 (m, 2H), 1.33 (d, J = 6.9 Hz, 3H); 13 C­{ 1 H} NMR (100 MHz, CDCl 3 ) δ = 178.6, 142.4, 133.5, 129.8, 127.6, 127.1, 126.9, 41.0, 32.1, 20.2. The analytical data are consistent with the literature …”

Pughiinin A, a Sesquiterpene from the FungusKionochaeta pughiiBCC 3878

“…The NMR data of pycnidione, mevalonolactone and 7-hydroxy-2-methylchromaonone were identical to those published [1], [2], [3], [4], [5]. The HMBC spectrum of 1 demonstrated the following correlations: H-17 to C-5a and C-6; H-7 to C-5a; H-8 to C-19; H-19 to C-8 and C-9, H-18 to C-8 and C-9, H-10 to C-8, C-9, C-12 and C-19; H-20 to C-11 and C-13; H-14 to C-5a, C-13 and C-15; H-2 to C-1, C-4 and C-16; H-4 to C-2 and C-4a; and H-16 to C-1, C-2 and C-15a.…”

“…The EtOAc extract of the culture broth of K. pughii was purified by a silica gel column chromatography and crystallization to yield pughiinin A (1), pycnidione (2) [1], mevalonolactone [2], [3], [4], and 7-hydroxy-2-methylchromanone [5]. The NMR data of pycnidione, mevalonolactone and 7-hydroxy-2-methylchromaonone were identical to those published [1], [2], [3], [4], [5].…”