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Synlett 2014; 25(16): 2355-2359
DOI: 10.1055/s-0034-1378581
DOI: 10.1055/s-0034-1378581
letter
Type 2 Ring-Opening Reactions of Cyclopropanated 7-Oxabenzonorbornadienes under Acid Catalysis
Further Information
Publication History
Received: 27 March 2014
Accepted after revision: 11 July 2014
Publication Date:
06 August 2014 (online)
![](https://www.thieme-connect.de/media/synlett/201416/lookinside/thumbnails/10.1055-s-0034-1378581-1.jpg)
Abstract
A novel ring-opening mode of cyclopropanated 7-oxabenzonorbornadiene under acid catalysis has been discovered, providing various 2-(alkoxymethyl)naphthalenes through the use of alcohol nucleophiles. The reaction was most effective with catalytic p-TsOH∙H2O in methanol, offering yields up to 91%. The compatibility of secondary and tertiary alcohols, as well as functionalized substrates was also demonstrated.
Key words
fused-ring systems - cyclopropane - ring-opening reactions - regioselectivity - acid catalysisSupporting Information
- for this article is available online at http://www.thieme-connect.com/products/ejournals/journal/ 10.1055/s-00000083.
- Supporting Information
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References and Notes
- 1 Bournaud C, Chung F, Luna AP, Pasco M, Errasti G, Lecourt T, Micouin L. Synthesis 2009; 869
- 2 Tam W, Cockburn N. Synlett 2010; 1170
- 3 Rayabarapu DK, Cheng C.-H. Acc. Chem. Res. 2007; 40: 971
- 4 Lautens M, Fagnou K, Heibert S. Acc. Chem. Res. 2003; 36: 48
- 5 Woo S, Keay BA. Synthesis 1996; 669
- 6 Chiu P, Lautens M. Top. Curr. Chem. 1997; 190: 1
- 7 Lautens M, Dockendorff C, Fagnou K, Malicki A. Org. Lett. 2002; 4: 1311
- 8 Lautens M, Dockendorff C. Org. Lett. 2003; 5: 3695
- 9 Duan J, Cheng C.-H. Tetrahedron Lett. 1993; 34: 4019
- 10 Feng C, Nandi TS, Cheng C.-H. J. Org. Chem. 1999; 64: 3538
- 11 Lautens M, Hiebert S. J. Am. Chem. Soc. 2004; 126: 1437
- 12 Wu MS, Jeganmohan M, Cheng C.-H. J. Org. Chem. 2005; 70: 9545
- 13 Leong P, Lautens M. J. Org. Chem. 2004; 69: 2194
- 14 Bertozzi F, Pineschi M, Macchia F, Arnold LA, Minnaard AJ, Feringa BL. Org. Lett. 2002; 4: 2703
- 15 Fan E, Shi W, Lowary TL. J. Org. Chem. 2007; 72: 2917
- 16 Madan S, Cheng C.-H. J. Org. Chem. 2006; 71: 8312
- 17 Lautens M, Rovis T. Tetrahedron 1999; 55: 8967
-
18 de Meijere A. Angew. Chem. Int. Ed. Engl. 1979; 18: 809
- 19 McKee M, Haner J, Carlson E, Tam W. Synthesis 2014; 46: 1518
- 20 Frejaville C, Jullien R. Tetrahedron Lett. 1971; 23: 2039
- 21 Bertz SH, Dabbagh G, Cook JM, Honkan V. J. Org. Chem. 1984; 49: 1739
- 22 Hughes S, Griffiths G, Stirling CJ. M. J. Chem. Soc., Perkin Trans. 2 1987; 1253
- 23 Carlson E, Haner J, McKee M, Tam W. Org. Lett. 2014; 16: 1776
- 24 Guan B.-T, Xiang S.-K, Wang B.-Q, Sun Z.-P, Wang Y, Zhao K.-Q, Shi Z.-J. J. Am. Chem. Soc. 2008; 130: 3268
- 25 Nakata D, Sakuma T, Kono K, Sato S, Tani S, Kunishima M. Chem. Pharm. Bull. 2001; 49: 97
- 26 Ahern C, Darcy R. Synth. Commun. 1998; 28: 971
- 27 Halton B, Kay AJ, Zhi-mei Z, Boese R, Haumann T. J. Chem. Soc., Perkin Trans. 1 1996; 1445
- 28 Scott K, Stonehouse J, Keeler J, Hwang T.-L, Shaka AJ. J. Am. Chem. Soc. 1995; 117: 4199
- 29 Shibata T, Ueno Y, Kanda K. Synlett 2006; 411
- 30 Engler TA, Shechter H. J. Org. Chem. 1999; 64: 4247
- 31 Hughes TS, Carpenter BK. J. Chem. Soc., Perkin Trans. 2 1999; 2291
- 32 Myers AG. Tetrahedron Lett. 1987; 28: 4493
- 33 Álvarez-Bercedo P, Martin R. J. Am. Chem. Soc. 2010; 132: 17352
- 34 General Procedure: In a small screw-cap vial containing a stir-bar, cyclopropanated oxabenzonorbornadiene 2 (1.0 equiv.) was dissolved in alcohol (0.5 mL). The reaction was cooled to 0 °C, and PTSA (0.1 equiv.) was added as a solid. The reaction was stirred at 0 °C for 10 min, then slowly warmed to r.t. The vial was sealed and secured tightly with polytetrafluoroethylene (PTFE) thread-seal tape and paraffin film, and heated to 90 or 110 °C with continuous stirring for 24–330 h. The crude product was directly loaded onto a chromatography column and purified (EtOAc–hexanes). 2-(Methoxymethyl)naphthalene (6a; Table 2, entry 1): Yield: 34.3 mg (82%); clear oil; Rf = 0.33 (EtOAc–hexanes, 1:9). 1H NMR (400 MHz, CDCl3): δ = 7.82–7.84 (m, 3 H), 7.78 (s, 1 H), 7.45–7.48 (m, 3 H), 4.62 (s, 2 H), 3.43 (s, 3 H). 13C NMR (100 MHz, CDCl3): δ = 135.7, 133.3, 133.0, 128.2, 127.9, 127.7, 126.5, 126.1, 125.9, 125.7, 74.8, 58.2. Spectral data are consistent with those previously reported.24 2-(Ethoxymethyl)naphthalene (6b; Table 2, entry 2): Yield: 25.3 mg (77%); clear oil; Rf = 0.40 (EtOAc–hexanes, 1:9). 1H NMR (400 MHz, CDCl3): δ = 7.80–7.82 (m, 3 H), 7.77 (s, 1 H), 7.44–7.47 (m, 3 H), 4.66 (s, 2 H), 3.57 (q, J = 7.0 Hz, 2 H), 1.26 (t, J = 7.0 Hz, 3 H). 13C NMR (100 MHz, CDCl3): δ = 136.1, 133.3, 133.0, 128.1, 127.9, 127.7, 126.3, 126.0, 125.8, 125.7, 72.8, 65.8, 15.3. Spectral data are consistent with those previously reported.24 2-(Butoxymethyl)naphthalene (6c; Table 2, entry 3 ): Yield: 37.1 mg (61%); clear oil; Rf = 0.40 (EtOAc–hexanes, 1:9). IR (neat): 3055 (s), 2958 (s), 2932 (s), 2869 (s), 1603 (m), 1509 (s), 1464 (s), 1374 (s), 1170 (m), 1098 (s), 854 (s), 816 (s), 751 (s) cm–1. 1H NMR (400 MHz, CDCl3): δ = 7.80–7.82 (m, 3 H), 7.76 (s, 1 H), 7.43–7.47 (m, 3 H), 4.65 (s, 2 H), 3.50 (t, J = 6.6 Hz, 2 H), 1.62 (m, 2 H), 1.40 (m, 2 H), 0.91 (t, J = 7.3 Hz, 3 H). 13C NMR (100 MHz, CDCl3): δ = 136.3, 133.3, 133.0, 128.1, 127.9, 127.7, 126.3, 126.0, 125.8, 125.7, 73.0, 70.3, 31.9, 19.4, 14.0. HRMS: m/z [M]+ calcd. for C15H18O: 214.1358; found: 214.1364. Spectral data are consistent with those previously reported.25 2-(Isopropoxymethyl)naphthalene (6d; Table 2, entry 5): Yield: 33.9 mg (67%); clear oil; Rf = 0.41 (EtOAc–hexanes, 1:9). IR (neat): 3055 (m), 2971 (s), 2930 (m), 2868 (m), 2242 (w), 1950 (w), 1726 (w), 1602 (m), 1509 (m), 1467 (m), 1369 (s), 1329 (s), 1124 (s), 1070 (s), 909 (m), 855 (m), 814 (s), 734 (s) cm–1. 1H NMR (400 MHz, CDCl3): δ = 7.79–7.83 (m, 4 H), 7.44–7.49 (m, 3 H), 4.67 (s, 2 H), 3.73 (m, 1 H), 1.23 (d, J = 6.0 Hz, 6 H). 13C NMR (100 MHz, CDCl3): δ = 136.7, 133.4, 132.9, 128.1, 127.9, 127.7, 126.1, 126.0, 125.8, 125.7, 71.0, 70.2, 22.2. HRMS: m/z [M]+ calcd. for C14H16O: 200.1201; found: 200.1205. 2-(Cyclohexoxymethyl)naphthalene (6e; Table 2, entry 6): Yield: 39.3 mg (67%); clear oil; Rf = 0.44 (EtOAc–hexanes, 1:9). IR (neat): 3055 (s), 2930 (s), 2855 (s), 1602 (m), 1509 (s), 1450 (s), 1366 (s), 1090 (s), 854 (m), 816 (s), 734 (s) cm–1. 1H NMR (400 MHz, CDCl3): δ = 7.79–7.83 (m, 4 H), 7.44–7.49 (m, 3 H), 4.71 (s, 2 H), 3.40 (m, 1 H), 2.00 (m, 2 H), 1.76 (m, 2 H), 1.54 (m, 1 H), 1.39 (m, 2 H), 1.25 (m, 3 H). 13C NMR (100 MHz, CDCl3): δ = 136.9, 133.4, 132.9, 128.0, 127.9, 127.7, 126.0, 125.9, 125.8, 125.7, 77.0, 69.8, 32.3, 25.9, 24.2. HRMS: m/z [M]+ calcd. for C17H20O: 240.1514; found: 240.1522. Spectral data are consistent with those previously reported.26 2-(tert-Butoxymethyl)naphthalene (6f; Table 2, entry 7): Yield: 7.1 mg (11%); clear oil; Rf = 0.40 (EtOAc–hexanes, 1:9). 1H NMR (400 MHz, CDCl3): δ = 7.77–7.84 (m, 4 H), 7.39–7.48 (m, 3 H), 4.59 (s, 2 H), 1.32 (s, 9 H). 13C NMR (100 MHz, CDCl3): δ = 137.4, 133.5, 132.8, 128.0, 127.9, 127.8, 127.6, 125.9, 125.8, 125.5, 73.6, 64.3, 27.8. Spectral data are consistent with those previously reported.24 1,4-Dimethoxy-6-(methoxymethyl)naphthalene (6g; Table 3, entry 2): Yield: 18.9 mg (56%); clear oil; Rf = 0.29 (EtOAc–hexanes, 1:9). IR (KBr): 3076 (w), 2996 (m), 2934 (s), 2833 (s), 1633 (w), 1604 (s), 1463 (s), 1361 (w), 1271 (s), 1246 (m), 1095 (s), 804 (s) cm–1. 1H NMR (600 MHz, CDCl3): δ = 8.18 (d, J = 8.6 Hz, 1 H), 8.13 (s, 1 H), 7.49 (dd, J = 8.6, 1.4 Hz, 1 H), 6.68 (ABq, J AB = 8.4 Hz, ΔδAB = 8.8 Hz, 2 H), 4.62 (s, 2 H), 3.941 (s, 3 H), 3.937 (s, 3 H), 3.39 (s, 3 H). 13C NMR (125 MHz, CDCl3): δ = 149.5, 135.7, 126.1, 125.8, 125.6, 122.2, 120.6, 103.4, 103.2, 74.9, 58.0, 55.7. HRMS: m/z [M]+ calcd. for C14H16O3: 232.1099; found: 232.1106. Spectral data are consistent with those previously reported.27 2,3-Dibromo-6-(methoxymethyl)naphthalene (6h; Table 3, entry 3): Yield: 12.8 mg (20%); red solid; mp 40–42 °C; Rf = 0.38 (EtOAc–hexanes, 1:9). IR (KBr): 3058 (w), 2989 (m), 2926 (s), 2884 (m), 2851 (m), 1582 (m), 1453 (m), 1102 (s), 903 (s), 888 (s), 821 (m) cm–1. 1H NMR (600 MHz, CDCl3): δ = 8.11 (s, 1 H), 8.10 (s, 1 H), 7.69 (m, 1 H), 7.65 (s, 1 H), 7.46 (m, 1 H), 4.58 (s, 2 H), 3.42 (s, 3 H). 13C NMR (100 MHz, CDCl3): δ = 137.4, 133.0, 132.6, 132.2, 132.0, 127.1, 127.0, 125.0, 122.3, 121.9, 74.4, 58.4. HRMS: m/z [M]+ calcd. for C12H10OBr2: 327.9098; found: 327.9108.2-(Methoxymethyl)-1,4-dimethylnaphthalene (6i; Table 3, entry 4): Yield: 41.7 mg (79%); beige solid; mp 39–42 °C; Rf = 0.54 (EtOAc–hexanes, 1:9). IR (KBr): 3070 (w), 2974 (m), 2923 (s), 2815 (m), 1716 (w), 1602 (w), 1512 (w), 1447 (m), 1389 (m), 1192 (m), 1104 (s), 1077 (m), 754 (s) cm–1. 1H NMR (600 MHz, CDCl3): δ = 8.11 (m, 1 H), 8.00 (m, 1 H), 7.52 (m, 2 H), 7.32 (s, 1 H), 4.64 (s, 2 H), 3.44 (s, 3 H), 2.67 (s, 3 H), 2.65 (s, 3 H). 13C NMR (125 MHz, CDCl3): δ = 133.0, 132.4, 132.3, 131.9, 130.6, 127.9, 125.4, 125.2, 124.6, 124.5, 73.3, 58.1, 19.3, 13.9. HRMS: m/z [M]+ calcd for C14H16O: 200.1201; found: 200.1207. 3-(Methoxymethyl)-1-methylnaphthalene (6j; Table 3, entry 5): Yield: 30.7 mg (73%); yellow oil; Rf = 0.32 (EtOAc–hexanes, 1:9). IR (neat): 3052 (w), 2980 (m), 2924 (s), 2918 (m), 1604 (m), 1509 (m), 1450 (m), 1193 (m), 1132 (m), 1100 (s), 910 (s), 868 (s), 734 (s) cm–1. 1H NMR (400 MHz, CDCl3): δ = 7.98 (d, J = 7.8 Hz, 1 H), 7.83 (d, J = 7.2 Hz, 1 H), 7.64 (s, 1 H), 7.53–7.46 (m, 2 H), 7.31 (s, 1 H), 4.58 (s, 2 H), 3.42 (s, 3 H), 2.69 (s, 3 H). 13C NMR (100 MHz, CDCl3): δ = 135.3, 134.7, 133.5, 132.2, 128.5, 126.4, 125.8, 125.7, 125.0, 124.0, 74.9, 58.2, 19.4. HRMS: m/z [M]+ calcd for C13H14O: 186.1045; found 186.1041.