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Synlett
Volumn , Issue 1, 2009, Pages 43-46
Modular total synthesis of lamellarin G trimethyl ether
Author keywords

Bromoarylation; Esterification; Friedel Crafts acylation; Lamellarins; Oxidative cyclization
Indexed keywords

EID: 62349114639     PISSN: 09365214     EISSN: 14372096     Source Type: Journal    
DOI: 10.1055/s-0028-1087387     Document Type: Article
Times cited : (40)
References (48)
  • 8
    • 62349139171 scopus 로고    scopus 로고
    • Quesada, A. R.; Garcia Gravalos, M. D.; Fernandez Puentes, J. L. WO 9701336 A1 970116, 2006; Chem. Abstr. 1996, 126, 166474.
    • (b) Quesada, A. R.; Garcia Gravalos, M. D.; Fernandez Puentes, J. L. WO 9701336 A1 970116, 2006; Chem. Abstr. 1996, 126, 166474.
  • 37
    • 34247132604 scopus 로고    scopus 로고
    • Toth, J.; Nedves, A.; Dancso, A.; Blasko, G.; Tocombining double acute accentke, L.; Nyerges, M. Synthesis 2007, 1003.
    • (p) Toth, J.; Nedves, A.; Dancso, A.; Blasko, G.; Tocombining double acute accentke, L.; Nyerges, M. Synthesis 2007, 1003.
  • 38
    • 34249811516 scopus 로고    scopus 로고
    • Tóth, J.; Varadi, L.; Dancso, A.; Blasko, G.; Tcombining double acute accentke, L.; Nyerges, M. Synlett 2007, 1259.
    • (q) Tóth, J.; Varadi, L.; Dancso, A.; Blasko, G.; Tcombining double acute accentke, L.; Nyerges, M. Synlett 2007, 1259.
  • 41
    • 62349088450 scopus 로고    scopus 로고
    • 4-(3,4-Dimethoxyphenyl)-4-oxobut-2-enoic acid (3) To a solution of veratrole (0.5 g, 3.6 mmol) and maleic anhydride (0.354 g, 3.6 mmol) in anhyd DCE (20 mL) was added anhyd AlCl3 powder (1.042 g, 7.8 mmol) in two portions. The reaction mixture was stirred for 1 h under reflux conditions. The reaction was hydrolyzed by adding 2.08 mL of H2O with vigorous stirring at 0°C, followed by neutralization with concd HCl (0.416 mL, The resulting mixture was extracted with EtOAc and purified by column chromatography on SiO2 to afford 0.72 g (85, of an acid as yellow solid; mp 178-179°C (lit.13a mp 178°C, no range given, 1H NMR (400 MHz, CDCl3, δ, 7.80 (dd, J, 12.4, 15.2 Hz, 1 H, 7.48 (m, 2 H, 6.88 (dd, J, 4.1, 8.2 Hz, 1 H, 6.67 (dd, J, 6.2, 15.8 Hz, 1 H, 3.88 (s, 6 H, 13C NMR 50 MHz, CDCl3, DMSO, δ, 186.4, 166.1, 150.4, 144.2, 135.3, 130.7, 1
    • 5: C, 61.01; H, 5.12. Found: C, 61.02; H, 5.14.
  • 43
    • 62349139170 scopus 로고    scopus 로고
    • Experimental Procedure, 4-(3,4-Dimethoxyphenyl)-4-oxobut-2-enoic Acid 3,4-Dimethoxyphenyl Ester (5) To a stirred solution of acid 3 (0.3 g, 1.27 mmol) in anhyd DMF (10 mL) was added DMAP (15.5 mg, 0.127 mmol) and 3,4-dimethoxy phenol (4, 0.19 g, 1.27 mmol, Afterwards, DCC (0.28 g, 1.37 mmol) was added to the above reaction mixture at 0°C and stirred for 5 min at 0°C and then 3 h at 20°C. Precipitated urea was filtered off and the filtrate was washed with 0.5 N HCl, followed by sat. NaHCO3 solution, and then dried over Na2SO4. The solvent was removed by evaporation, and the resulting crude reaction mixture was purified by column chromatography on SiO2 to give 0.42 g (83, of ester. 1H NMR (200 MHz, CDCl3, δ, 6.62 (d, J, 8.6 Hz, 3 H, 6.40 (d, J, 2.3 Hz, 3 H, 6.28 (dd, J, 3.1, 8.5 Hz, 2 H, 3.73 (d, J, 7.8 Hz, 12 H, 13C NMR 75 MHz, CDC
    • 7: C, 64.51; H, 5.41. Found: C, 64.54; H, 5.44.
  • 45
    • 62349100021 scopus 로고    scopus 로고
    • 3-Bromo-4-(3,4-Dimethoxybenzoyl)-6,7-dimethoxychroman-2-one (6) The ester (0.2 g, 0.53 mmol) was treated with NBS (0.1 g, 0.59 mmol) and Sm(OTf)3 (0.032 g, 0.053 mmol) in MeCN at 20°C to produce 0.22 g (93, of 6, as an exclusively endo-cyclized product. 1H NMR (200 MHz, CDCl3, δ, 7.23 (s, 1 H, 7.18 (s, 1 H, 6.83 (s, 1 H, 6.54 (s, 2 H, 6.05 (s, 1 H, 5.09 (s, 1 H, 3.80 (m, 12 H, 13C NMR (75 MHz, CDCl3, δ, 202.6, 166.5, 149.9, 146.5, 143.7, 135.7, 116.8, 114.9, 106.9, 103.6, 100.6, 99.7, 95.5, 94.6, 56.8, 56.7, 56.5, 56.2, 56.0. IR neat, 3422, 2925, 2853, 2361, 1713, 1657, 1593, 1507, 1455, 1406, 1204, 1035, 977, 846, 798, 760, 666, 593 cm-1. ESI-MS: m/z, 450 [M, 490 [M, 39, 423, 403, 375, 336, 306, 285, 258, 229, 208, 142. Anal. Calcd for C20H 19BrO7: C, 53.23; H, 4.24. Found: C, 53.26; H, 4.22
    • 7: C, 53.23; H, 4.24. Found: C, 53.26; H, 4.22.
  • 48
    • 62349138296 scopus 로고    scopus 로고
    • 13-(3,4-Dimethoxy-phenyl)-2,3,10,11-tetramethoxy-7, 8-dihydro-5-oxa-6b-aza-dibenzo[a,i]fluoren-6-one (Lamellarin G Trimethyl Ether, 1) The bromide 6 (0.05 g, 0.11 mmol) was added to 6,7-dimethoxy-1,2,3,4-tetrahydro isoquinoline (0.51 g, 2.22 mmol) and K 2CO3 (0.10 g, 0.73 mmol) in MeCN (3 mL) with continuous stirring under aerobic conditions. The mixture was stirred under reflux for 2 h, and then the reaction mixture was quenched with H2O and extracted with EtOAc (3 x 10 mL) and purified by column chromatography on SiO2 to afford 0.038 g (63, of lamellarin G trimethyl ether as white solid; mp 238-239°C (lit.11 mp 239.1-240°C, 1H NMR (300 MHz, CDCl3, δ, 7.05 (m, 3 H, 6.88 (s, 1 H, 6.75 (s, 1 H, 6.69 (s, 1 H, 6.64 (s, 1 H, 4.78 (m, 2 H, 3.92 (s, 3 H, 3.88 (s, 3 H, 3.87 (s, 3 H, 3.84 (s, 3 H, 3.46 (s, 3 H, 3.34 (s, 3 H, 3.10 t, J, 6.6 Hz, 2 H
    • 8: C, 68.50; H, 5.38; N, 2.58. Found: C, 68.48; H, 5.36; N, 2.54.

* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.