Bi(OTf)3-CATALYZED OXA–PICTET–SPENGLER REACTION
923
1
4-(3,4-Dihydro-6-methoxy-1H-isochromen-1-yl)benzonitrile (Entry 9). H
NMR (CDCl3, 300 MHz) d 2.79 (m, 1H), 3.13 (m, 1H), 3.79 (s, 3H), 3.91 (m, 1H),
4.14 (m, 1H), 5.72 (s, 1H), 6.58 (d, J ¼ 8.5 Hz, 1H), 6.66 (dd, J ¼ 8.5 Hz, J ¼ 2.57,
1H), 6.71 (d, J ¼ 2.5 Hz, 1H), 7.43 (d, J ¼ 8.2 Hz, 2H), 7.64 (d, J ¼ 8.4 Hz, 2H);
13C NMR (CDCl3, 75 MHz) d 28.9, 55.2, 63.9, 78.5, 111.8, 112.5, 113.4, 118.7,
127.6, 128.1, 129.3, 132.2, 135.0, 147.6, 158.4; LRMS: (DCI=NH3, m=z) calc. for
C17H15NO2: 265.1. Found: 283.1 ðM þ NHþ4 Þ.
3,4-Dihydro-6-methoxy-1-(2-methoxyphenyl)-1H-isochromene (Entry
10). 1H NMR (CDCl3, 300 MHz) d 2.82 (m, 1H), 3.13 (m, 1H), 3.80 (s, 3H),
3.91 (s, 3H), 3.96 (m, 1H), 4.20 (m, 1H), 6.27 (s, 1H), 6.71 (m, 3H), 6.92 (t,
J ¼ 7.5 Hz, 1H), 6.98 (d, J ¼ 8.1 Hz, 1H), 7.13 (dd, J ¼ 7.6 Hz, J ¼ 1.7 Hz, 1H), 7.30
(td, J ¼ 7.5 Hz, J ¼ 1.7 Hz, 1H); 13C NMR (CDCl3, 75 MHz) d 29.1, 55.0, 55.4,
63.4, 72.0, 110.6, 112.2, 112.9, 120.4, 127.6, 128.9, 129.7, 129.9, 130.8, 135.2,
157.3, 157.8; LRMS: (DCI=NH3, m=z) calc. for C17H18O3: 270.1. Found: 271.1
(M þ Hþ).
5,7-Dihydro-7-(4-nitrophenyl)-4H-thieno[2,3-c]pyran (Entry 11). 1H
NMR (CDCl3, 300 MHz) d 2.74 (m, 1H), 3.01 (m, 1H), 3.94 (m, 1H), 4.26 (m,
1H), 5.89 (s, 1H), 6.87 (d, J ¼ 5.1 Hz, 1H), 7.19 (dd, J ¼ 5.1 Hz, J ¼ 0.7 Hz, 1H),
7.59 (d, J ¼ 8.7 Hz, 2H), 8.23 (d, J ¼ 8.8 Hz, 2H); 13C NMR (CDCl3, 75 MHz) d
26.0, 64.5, 76.7, 123.8, 124.3, 127.1, 128.3, 134.0, 135.1, 147.8, 148.5; LRMS:
(DCI=NH3, m=z) calc. for C13H11NO3S: 261.0. Found: 279.0 ðM þ NHþ4 Þ.
5,7-Dihydro-7-(4-methoxyphenyl)-4H-thieno[2,3-c]pyran (Entry 12). 1H
NMR (CDCl3, 300 MHz) d 2.71 (m, 1H), 2.98 (m, 1H), 3.81 (s, 3H), 3.90 (m, 1H),
4.24 (m, 1H), 5.75 (s, 1H), 6.86 (d, J ¼ 5.1 Hz, 1H), 6.89 (d, J ¼ 8.8 Hz, 2H), 7.17
(dd, J ¼ 5.0 Hz, J ¼ 0.8 Hz, 1H), 7.32 (d, J ¼ 8.7 Hz, 2H); 13C NMR (CDCl3,
75 MHz) d 26.2, 55.2, 64.2, 77.3, 113.8, 123.7, 126.8, 129.2, 133.8, 137.2, 159.7;
LRMS: (DCI=NH3, m=z) calc. for C14H12O2S: 246.1. Found: 247.0 (M þ Hþ).
4-(5,7-Dihydro-4H-thieno[2,3-c]pyran-7-yl)benzonitrile (Entry 13). 1H
NMR (CDCl3, 300 MHz) d 2.73 (m, 1H), 3.00 (m, 1H), 3.92 (m, 1H), 4.25 (m,
1H), 5.84 (s, 1H), 6.87 (d, J ¼ 5.0 Hz, 1H), 7.19 (dd, J ¼ 5.0 Hz, J ¼ 0.6 Hz, 1H),
7.52 (d, J ¼ 8.3 Hz, 2H), 7.66 (d, J ¼ 8.4 Hz, 2H); 13C NMR (CDCl3, 75 MHz) d
26.0, 64.3, 76.9, 112.1, 118.6, 124.2, 127.0, 128.1, 132.3, 133.9, 135.1, 146.6; LRMS:
(DCI=NH3, m=z) calc. for C14H11NOS: 241.1. Found: 259.0 ðM þ NHþ4 Þ.
5,7-Dihydro-7-pentyl-4H-thieno[2,3-c]pyran (Entry 14). 1H NMR (CDCl3,
300 MHz) d 0.91 (m, 3H), 1.34 (m, 4H), 1.54 (m, 2H), 1.80 (m, 2H), 2.59 (m, 1H),
2.87 (m, 1H), 3.75 (m, 1H), 4.19 (m, 1H), 4.75 (m, 1H), 6.81 (d, J ¼ 5.0 Hz, 1H),
7.13 (dd, J ¼ 5.0 Hz, J ¼ 0.6 Hz, 1H); 13C NMR (CDCl3, 75 MHz) d 14.0, 22.6,
24.9, 26.3, 31.8, 37.4, 64.4, 75.2, 122.4, 127.1, 133.2, 137.8; LRMS: (DCI=NH3,
m=z) calc. for C12H18OS: 210.1. Found: 228.1 ðM þ NHþ4 Þ.
1,3,4,9-Tetrahydro-1-(4-nitrophenyl)pyrano[3,4-b]indole (Entry 15). 1H
NMR (CDCl3, 300 MHz) d 2.87 (m, 1H), 3.12 (m, 1H), 4.02 (m, 1H), 4.31 (m,
1H), 5.91 (s, 1H), 7.18 (m, 2H), 7.27 (d, J ¼ 7.1 Hz, 1H), 7.49 (br s, 1H), 7.57 (d,
J ¼ 8.7 Hz, 2H þ 1H), 8.22 (d, J ¼ 8.7 Hz, 2H); 13C NMR (CDCl3, 75 MHz) d
22.1, 64.9, 75.0, 109.3, 111.1, 118.5, 120.0, 122.5, 124.0, 126.8, 129.1, 131.9,