7466
R. Mahrwald, S. Quint / Tetrahedron 56 (2000) 7463–7468
nate (3c). Yield: 2.22 g (67%). 1H NMR (300 MHz, CDCl3)
d 7.20–7.50 (m, 10H), 6.32 (s, 1H), 3.93 (d, 2H, J7 Hz),
1.94 (m, 1H), 0.89 (d, 6H, J7 Hz); 13C NMR (75 MHz,
CDCl3) d 154.00, 132.08, 129.16, 128.31, 121.56, 86.00,
82.30, 74.86, 57.98, 27.81, 18.89. HRMS: m/z calcd for
C17H11O 231.0810. Found: 231.0815.
21.8. MS: m/z (relative intensity) 250 (0.05, [Mϩ]), 207
(0.26), 192 (48%); 191 (1), 189 (0.31), 179 (0.33), 129
(0.39), 105 (0.32), 77 (0.32), 43 (0.25). HRMS: m/z calcd
for C18H18O 251.1436. Found: 251.1427.
tButyl-(1,3-diphenyl-prop-2-ynyl)-ether (2d). 1H NMR
(300 MHz, CDCl3) d 7.20–7.60 (m, 10H), 5.41 (s, 1H);
1.31 (s, 9H); 13C NMR (75 MHz, CDCl3) d 140.91,
131.62, 128.47, 128.23, 128.21, 127.81, 127.04, 123.21,
90.68, 85.81, 75.72, 64.63, 28.51. MS: m/z (relative inten-
sity) 208 (0.13), 191 (0.39), 105 (1), 77 (0.61), 51 (0.25).
HRMS: m/z calcd for C19H20O 264.1514. Found 264.1505.
1-[(1-Phenyl-1-methyl)-prop-2-ynyl]-ibutylcarbonate (3d).
Yield: 1.51 g (20%, from the commercial available alcohol).
1H NMR (300 MHz, CDCl3) d 7.20–7.60 (m, 5H), 3.90 (d,
2H, J7 Hz), 2.90 (s, 1H), 2.90 (m, 3H), 0.95 (d, 3H,
J7 Hz), 0.94 (d, 6H, J7 Hz); 13C NMR (75 MHz,
CDCl3) d 152.81, 141.63, 128.43, 128.19, 124.86, 82.53,
77.41, 76.03, 73.95, 32.28, 27.73, 18.85. HRMS: m/z
calcd for C10H9O 145.0653. Found: 145.0651.
Benzyl-(1,3-diphenyl-prop-2-ynyl)-ether (2e). 1H NMR
(300 MHz, CDCl3) d 7.49–7.88 (m, 15H), 5.70 (s, 1H),
5.04 (d, 1H, J11.7 Hz), 4.97 (d, 1H, J11.7 Hz); 13C
NMR (75 MHz, CDCl3) d 138.94, 138.08, 132.01, 128.81,
128.74, 128.62, 128.53, 128.31, 128.04, 127.81, 122.81,
88.12, 87.22, 71.21, 70.36. MS: m/z (relative intensity)
212 (0.11), 191 (0.05), 121 (0.1), 104 (1), 91 (0.6), 77
(0.8), 65 (0.2), 51 (0.43), 39 (0.15). HRMS: m/z calcd for
C22H18O 298.1358. Found 298.1348.
1-(1-Phenyl-prop-2-ynyl)-ibutylcarbonate (3e). Yield:
1
6.12 g (88%, from the commercial available alcohol). H
NMR (300 MHz, CDCl3) d 7.10–7.40 (m, 5H), 6.14 (d,
1H, J2 Hz), 3.81 (m, 2H), 2.58 (d, 1H, J2 Hz), 1.80
(spt, 1H, 7 Hz), 0.80 (d, 3H, J7 Hz), 0.79 (d, 3H, J
7 Hz); 13C NMR (75 MHz, CDCl3) d 154.40, 135.91,
129.31, 128.73, 127.75, 79.71, 76.35, 74.59, 69.09, 27.75,
18.87. HRMS: m/z calcd for C9H7O 131.0497. Found:
131.0495.
Methyl-(1-phenyl-hept-2-ynyl)-ether (2f).7 1H NMR
(300 MHz, CDCl3) d 7.20–7.60 (m, 5H), 5.07 (tr, 1H, J
2 Hz), 3.40 (s, 3H), 2.29 (dtr, 2H, J7, 2 Hz), 1.30–1.55 (m,
4H), 0.84 (tr, 3H, J7 Hz); 13C NMR (75 MHz, CDCl3) d
139.11, 128.41, 128.28, 127.43, 88.77, 77.52, 73.21, 55.63,
30.75, 22.02, 18.51, 13.62.
[1-(Hex-1-ynyl)-hept-2-ynyl]-ibutylcarbonate (3f). Yield:
1.03 g (35%). 1H NMR d 5.82 (q, 1H, J2 Hz), 3.89 (d, 2H,
J7 Hz), 2.15 (trd, 4H, J7, 2 Hz), 1.91 (hpt, 1H, J7 Hz),
1.15–1.5 (m, 8H), 0.89 (d, 6H, J7 Hz), 0.83 (t, 6H, J
7 Hz); 13C NMR (75 MHz, CDCl3) d 154.02, 86.84, 74.27,
74.48, 57.73, 30.17, 27.76, 21.86, 18.84, 18.41, 13.53.
HRMS: m/z calcd for C13H19O 191.1436. Found: 191.1435.
Ethyl-(1-phenyl-hept-2-ynyl)-ether (2g).6 1H NMR (300
MHz, CDCl3) d 7.10–8.10 (m, 5H), 5.04 (1H); m 3.60 (s,
1H); 3.40 (m, 1H), 2.17 (tr, 2H), 1.30–1.50 (m, 4H), 1.14 (tr,
3H), 0.83 (tr, 3H); 13C NMR (75 MHz, CDCl3) d 139.62,
128.37, 128.07, 127.38, 88.12, 78.19, 71.65, 63.54, 30.75,
22.00, 18.58, 15.20, 13.60.
General procedure for the TiCl4-mediated displacement
reaction
iPropyl-(1-phenyl-hept-2-ynyl)-ether (2h). 1H NMR
(300 MHz, CDCl3) d 7.14–7.39 (m, 5H), 5.07 (s, 1H),
3.85 (q, 1H, J6.0 Hz), 2.13 (tr, 2H, J7.2 Hz), 1.22–
1.47 (m, 4H), 1.11 (d, 3H, J6.4 Hz), 1.07 (d, 3H, J
6 Hz), 0.78 (t, 3H, J7.2 Hz); 13C NMR (75 MHz,
CDCl3) d 140.33, 128.38, 127.91, 127.34, 87.42, 78.91,
69.21, 69.14, 30.76, 21.91, 22.82, 21.71, 18.62, 13.61.
MS: m/z (relative intensity) 231 (0.03, [Mϩ1]), 230 (0.13,
[Mϩ]), 187 (0.14), 171 (0.2), 145 (0.22), 129 (0.51),
115 (0.38), 105 (1), 91 (0.58), 77 (0.61), 57 (0.50),
43 (0.51). HRMS: m/z calcd for C16H22O 230.1671. Found
230.1672.
TiCl4 (42 mg, 0.22 mmol) was carefully added to a stirred
solution of the corresponding propargylic ester (2.2 mmol)
in the corresponding abs. alcohols (5.0 mL). The reaction
mixture was stirred for 24 h at rt. The solution was poured
into aqu. NaHCO3 solution and extracted several times with
diethyl ether. The organic layers were separated, dried
(Na2SO4), concentrated in vacuum and purified by chroma-
tography. Compounds 2a–2m were isolated as oils. The
yields are given in Table 1.
Methyl-(1,3-diphenyl-prop-2-ynyl)-ether (2a).5 1H NMR
(300 MHz, CDCl3) d 7.20–7.60 (m, 10H), 5.23 (s, 1H), 3.41
(s, 3H); 13C NMR (75 MHz, CDCl3) d 138.54, 131.82,
128.56, 128.49, 128.32, 127.54, 122.57, 87.78, 73.53, 55.94.
Phenyl-(1-phenyl-hept-2-ynyl)-ether (2i). 1H NMR
(300 MHz, CDCl3) d 6.33–7.56 (m, 10H), 5.09 (s, 1H),
2.45 (tr, 2H, J6 Hz), 1.45–1.64 (m, 4H), 1.09 (tr, 3H,
J7.2 Hz); 13C NMR (75 MHz, CDCl3) d 155.42, 135.02,
129.81, 129.24, 128.63, 127.91, 126.72, 120.28, 115.56,
85.33, 81.11, 42.61, 31.21, 21.13, 18.72, 13.76. MS: m/z
(relative intensity) 264 (0.15), 221 (0.2), 207 (0.1), 183
(0.1), 95 (0.2), 94 (1), 66 (0.65), 65 (0.6). HRMS: m/z
calcd for C19H20O 264.1514. Found 264.1518.
Ethyl-(1,3-diphenyl-prop-2-ynyl)-ether (2b).6 1H NMR
(300 MHz, CDCl3) d 8.05–7.20 (m, 10H), 5.30 (s, 1H),
3.66 (q, 2H), 1.19 (tr, 3H); 13C NMR (75 MHz, CDCl3) d
138.99, 131.80, 128.52, 128.47, 128.34, 128.28, 127.48,
122.66, 87.32, 71.92, 67.95, 63.94, 15.24.
1
iPropyl-(1,3-diphenyl-prop-2-ynyl)-ether (2c). H NMR
(300 MHz, CDCl3) d 7.20–7.53 (m, 10H), 5.35 (s, 1H),
3.98 (spt,1H, J6 Hz), 1.21 (d, 3H, J6 Hz), 1.18 (d, 3H,
J6 Hz); 13C NMR (75 MHz, CDCl3) d 139.6, 131.8,
128.5, 128.4, 127.4, 122.8, 88.1, 86.6, 69.8, 69.4, 22.9,
Methyl-[1-(1-thiophen-2-yl)-hept-2-ynyl]-ether (2j). 1H
NMR (300 MHz, CDCl3) d 7.39–7.45 (m, 2H), 7.22–7.28
(m, 4H), 7.16 (ddd, 1H, J3–4, 1, 1 Hz), 6.92 (dd, 1H, J5,