mmol, 85% by volume) and methanolic CAN (4.68 g, 8.50
mmol, 30 cm3) to afford the desired compound 16c as a pale
yellow oil (0.34 g, 66%); νmax(film)/cmϪ1 3296, 3074, 2118, 1587,
1266, 1092; δH(300 MHz: CDCl3) 8.31 (1H, d, J 3, ArH), 7.98
(1H, dd, J 9 and 3, ArH), 6.85 (1H, d, J 9, ArH), 4.46 (1H, dt,
J 12 and 2, OCH), 4.21 (1H, dd, J 12 and 5, OCH), 3.95 (1H, br
6-Chloro-4-ethynyl-3-(1-fluoro-1-methylethyl)chromane 16f.
The one-pot procedure was used for the synthesis of compound
16f using propynyl alcohol 15f (1.02 g, 4.1 mmol) in anhydrous
DCM (20 cm3), octacarbonyldicobalt (1.53 g, 4.5 mmol),
tetrafluoroboric acid diethyl ether complex (0.82 cm3, 4.5
mmol, 85% by volume) and methanolic CAN (10.03 g, 18.33
mmol, 40 cm3) to afford the desired compound 16f (0.72 g,
70%) as a yellow oil; νmax(film)/cmϪ1 3298, 3069, 2117, 1581,
1239; δH(300 MHz: CDCl3) 7.36 (1H, d, J 2, ArH), 7.08 (1H,
dd, J 8 and 2, ArH), 6.73 (1H, d, J 8, ArH), 4.36 (1H, dt, J 12
᎐
s, PhCH), 2.39 (1H, m, CH), 2.36 (1H, d, J 2, ᎐CH), 1.45 (3H,
᎐
d, JHF 22, CH3), 1.37 (3H, d, JHF 22, CH3); δC(75.45 MHz:
CDCl3) 159.13 (s), 141.64 (s), 126.30 (d), 124.29 (d), 122.03
(s), 117.59 (d), 94.60 (d, JCF 169, CF), 84.72 (d), 72.34 (s),
65.00 (t), 46.07 (d), 28.02 (d), 2 × 25.55 (q); δF(282.40 MHz:
CDCl3) Ϫ137.53 [1F, d of septets, J 21 and 9, (CH3)2CF ]
(Found: Mϩ, 263.0958. C14H14FNO3 requires M, 263.0958); m/z
263 (Mϩ), 247, 228, 200 (100%), 186, 176, 154, 129, 101, 89, 75,
61, 41.
and 2, OCH), 4.11 (1H, dd, J 12 and 5, OCH), 3.86 (1H, br s,
᎐
PhCH), 2.32 (1H, m, CH), 2.29 (1H, d, J 3, ᎐CH), 1.43 (3H, d,
᎐
JHF 22, CH3), 1.35 (3H, d, JHF 22, CH3); δC(75.45 MHz: CDCl3)
153.49 (s), 129.55 (d), 128.45 (d), 127.03 (s), 122.86 (s), 118.37
(d), 92.59 (d, JCF 169, CF), 85.61 (d), 71.16 (s), 64.35 (t), 47.15
(d), 27.80 (d), 25.81 (q), 25.22 (q); δF(282.40 MHz: CDCl3)
Ϫ136.38 [1F, d of septets, J 22 and 12, (CH3)2CF ] (Found: Mϩ,
252.0717. C14H13ClFO requires M, 252.0717); m/z 252 (Mϩ),
231, 217, 189 (100%), 182, 157, 136, 113, 101, 87, 75, 61, 53, 41
(Found: C, 66.31; H, 5.55. Calc. for C14H13ClFO: C, 66.64; H,
5.58%).
6-Nitro-4-ethynyl-3-(1-methylethenyl)chromane 23. This was
prepared using propynyl alcohol 15c (0.15 g, 0.6 mmol) in
anhydrous DCM (5 cm3), octacarbonyldicobalt (0.22 g, 0.6
mmol), tetrafluoroboric acid diethyl ether complex (0.12 cm3,
0.6 mmol, 85% by volume). After nineteen hours methanolic
CAN (1.42 g, 2.6 mmol, 20 cm3) was added to afford the desired
compound 23 (0.06 g, 42%) as a pale yellow oil, νmax(film)/cmϪ1
3293, 3066, 2114, 1639, 1589, 1239; δH(300 MHz: CDCl3) 8.46
(1H, dd, J 3 and 1, ArH), 8.04 (1H, dd, J 8 and 3, ArH), 6.87
(1H, d, J 8, ArH), 5.09 (1H, t, J 1, ᎐CH), 4.91 (1H, br s, ᎐CH),
6-Methoxy-4-ethynyl-3-(1-fluoro-1-methylethyl)chromane
16g. The one-pot procedure was used for the synthesis of com-
pound 16g using propynyl alcohol 15g (0.75 g, 3.1 mmol) in
anhydrous DCM (12 cm3), octacarbonyldicobalt (0.95 g, 3.2
mmol), tetrafluoroboric acid diethyl ether complex (0.55 cm3,
3.2 mmol, 85% by volume) and methanolic CAN (7.52 g, 13.70
mmol, 40 cm3) to afford the desired compound 16g as a pale
yellow oil (0.50 g, 64%); νmax(film)/cmϪ1 3291, 3072, 2116, 1589,
1258, 1029; δH(300 MHz: CDCl3) 7.05 (1H, d, J 2, ArH), 6.89
(1H, dd, J 8 and 2, ArH), 6.64 (1H, d, J 2, ArH), 4.39 (1H, ddd,
J 12, 3 and 2, OCH), 4.18 (1H, dd, J 12 and 5, OCH), 3.87 (1H,
br s, PhCH), 3.69 (3H, s, OMe), 2.34 (1H, m, CH), 2.26 (1H, d,
᎐
᎐
4.38 (1H, dd, J 11 and 3, OCH), 3.93 (2H, m, PhCH and OCH),
᎐
2.71 (1H, dt, J 11 and 3, CH), 2.33 (1H, d, J 2, ᎐CH), 1.88
᎐
(3H, s, CH3) (Found: Mϩ, 243.0895. C14H13NO3 requires M,
243.0895); m/z 243 (Mϩ), 219, 200, 182, 168, 152, 130, 115, 101,
91, 76, 69 (100%), 58, 52, 42.
6,8-Dibromo-4-ethynyl-3-(1-fluoro-1-methylethyl)chromane
16d. The one-pot procedure was used for the synthesis of com-
pound 16d using propynyl alcohol 15d (1.00 g, 2.7 mmol) in
anhydrous DCM (20 cm3), octacarbonyldicobalt (1.00 g, 2.9
mmol), tetrafluoroboric acid diethyl ether complex (0.50 cm3,
2.9 mmol, 85% by volume) and methanolic CAN (6.62 g, 12.1
mmol, 40 cm3) to afford the desired compound 16d (0.61 g,
62%) as a yellow oil; νmax(film)/cmϪ1 3295, 3074, 2117, 1562,
1243; δH(300 MHz: CDCl3) 7.33 (1H, d, J 2, ArH), 7.24 (1H, d,
J 2, ArH), 4.25 (1H, dt, J 12 and 2, OCH), 4.02 (1H, dd, J 12
᎐
J 2, ᎐CH), 1.44 (3H, d, JHF 22, CH3), 1.28 (3H, d, JHF 22, CH3);
᎐
δC(75.45 MHz: CDCl3) 156.70 (s), 154.10 (s), 132.59 (d), 112.16
(s), 106.71 (d), 100.42 (d), 95.36 (d, JCF 168, CF), 87.04 (d),
71.65 (s), 65.90 (t), 55.92 (q), 47.26 (d), 26.62 (d), 24.17 (q),
24.03 (q); m/z 248 (Mϩ), 227, 213, 185, 171 (100%), 162, 145,
116, 102, 89, 63, 51, 41 (Found: C, 72.49; H, 6.84. Calc. for
C15H17FO2: C, 72.58; H, 6.85%).
and 5, OCH), 3.70 (1H, br s, PhCH), 2.15 (1H, m, CH), 2.11
6,8-Diiodo-4-ethynyl-3-(1-fluoro-1-methylethyl)chromane 16h.
The one-pot procedure was used for the synthesis of compound
16h using propynyl alcohol 15h (0.50 g, 1.1 mmol) in anhydrous
DCM (15 cm3), octacarbonyldicobalt (0.41 g, 1.2 mmol),
tetrafluoroboric acid diethyl ether complex (0.21 cm3, 1.2
mmol, 85% by volume) and methanolic CAN (2.64 g, 4.8 mmol,
20 cm3) to afford the desired compound 16h (0.36 g, 71%) as a
yellow oil; νmax(film)/cmϪ1 3294, 3062, 2116, 1574, 1238; δH(300
MHz: CDCl3) 7.90 (1H, d, J 2, ArH), 7.64 (1H, J 2, ArH), 4.44
(1H, ddd, J 12, 3 and 2, OCH), 4.20 (1H, dd, J 12 and 5, OCH),
᎐
(1H, d, J 3, ᎐CH), 1.24 (3H, d, J 22, CH3), 1.13 (3H, d, JHF
᎐
HF
22, CH3); δC(75.45 MHz: CDCl3) 149.90 (s), 134.21 (d), 131.83
(d), 124.60 (s), 113.02 (s), 111.77 (s), 94.68 (d, JCF 169, CF),
85.19 (d), 71.84 (s), 65.06 (t), 45.71 (d), 27.92 (d), 25.68 (q),
25.36 (q); δF(282.40 MHz: CDCl3) Ϫ136.71 [1F, d of septets,
J 22 and 12, (CH3)2CF] [Found: Mϩ, 375.9297. C14H13Br2FO
(79Br81Br) requires M, 375.9297]; m/z 376 (Mϩ), 341, 313
(100%), 288, 260, 234, 207, 181, 155, 126, 99, 61, 41 (Found: C,
43.67; H, 3.76. Calc. for C14H13Br2FO: C, 44.71; H, 3.48%).
7-Methoxy-4-ethynyl-3-(1-fluoro-1-methylethyl)chromane
16e. The one-pot procedure was used for the synthesis of com-
pound 16e using propynyl alcohol 15e (0.75 g, 3.1 mmol) in
anhydrous DCM (15 cm3), octacarbonyldicobalt (0.95 g, 3.2
mmol), tetrafluoroboric acid diethyl ether complex (0.55 cm3,
3.2 mmol, 85% by volume) and methanolic CAN (7.52 g, 13.7
mmol, 40 cm3) to afford the desired compound 16e (0.48 g,
63%) as a yellow oil; νmax(film)/cmϪ1 3293, 3071, 2115, 1589,
1251, 1036; δH(300 MHz: CDCl3) 7.25 (1H, d, J 2, ArH), 6.53
(1H, dd, J 8 and 2, ArH), 6.36 (1H, d, J 2H, ArH), 4.37 (1H,
ddd, J 12, 3 and 2, OCH), 4.11 (1H, dd, J 12 and 5, OCH), 3.83
3.84 (1H, br s, PhCH), 2.35 (1H, m, CH), 2.31 (1H, d, J 3,
᎐
᎐CH), 1.43 (3H, d, J 22, CH3), 1.31 (3H, d, JHF 22, CH3);
᎐
HF
δC(75.45 MHz: CDCl3) 152.78 (s), 145.36 (d), 138.76 (d), 124.28
(s), 115.02 (s), 118.77 (s), 94.69 (d, JCF 169, CF), 85.28 (d), 71.83
(s), 65.23 (t), 46.83 (d), 27.90 (d), 25.73 (q), 25.40 (q); δF(282.40
MHz: CDCl3) Ϫ136.81 [1F, d of septets, J 22 and 12, (CH3)2-
CF]; m/z 421 (Mϩ Ϫ 49), 407 (100%), 382, 354, 308, 282, 255,
227, 201, 181, 155, 127, 100, 61, 52, 41 (Found: C, 35.65; H,
2.69. Calc. for C14H13I2FO: C, 35.78; H, 2.79%).
6-Bromo-4-ethynyl-3-(1-fluoro-1-methylethyl)chromane 16i.
The one-pot procedure was used for the synthesis of compound
16i using propynyl alcohol 15i (0.80 g, 2.7 mmol), octacarb-
onyldicobalt (1.02 g, 3.0 mmol), tetrafluoroboric acid diethyl
ether complex (0.52 cm3, 3.0 mmol, 85% by volume) and meth-
anolic CAN (6.67 g, 12.20 mmol, 30 cm3) to afford the desired
compound 16i (0.53 g, 66%) as a yellow oil; νmax(film)/cmϪ1
3295, 3071, 2117, 1591, 1242; δH(300 MHz: CDCl3) 7.50 (1H, br
s, ArH), 7.20 (1H, br d, J 8, ArH), 6.67 (1H, d, J 8, ArH), 4.35
(1H, dd, J 12 and 3, OCH), 4.09 (1H, dd, J 12 and 5, OCH),
3.86 (1H, br s, PhCH), 2.33 (1H, m, CH), 2.29 (1H, d, J 3,
(1H, br s, PhCH), 3.76 (3H, s, OMe), 2.33 (1H, m, CH), 2.25
᎐
(1H, d, J 2, ᎐CH), 1.45 (3H, d, JHF 22, CH3), 1.36 (3H, d, JHF 22,
᎐
CH3); δC(75.45 MHz: CDCl3) 159.70 (s), 154.65 (s), 130.50 (d),
113.41 (s), 108.46 (d), 101.47 (d), 95.21 (d, JCF 168, CF), 86.84
(d), 70.34 (s), 64.15 (t), 55.28 (q), 47.19 (d), 27.25 (d), 25.71 (q),
25.18 (q); δF(282.40 MHz: CDCl3) Ϫ135.76 [1F, d of septets,
J 22 and 12, (CH3)2CF ] (Found: Mϩ, 248.1213. C15H17FO2
requires M, 248.1213]; m/z 248 (Mϩ), 227, 213, 187 (100%), 171,
160, 145, 132, 117, 102, 89, 63, 53, 41.
1436
J. Chem. Soc., Perkin Trans. 1, 1998