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Y. Cui et al. / Tetrahedron 69 (2013) 7618e7626
(200 mg), DDQ (395 mg, 1.74 mmol), and DCE (14 mL). After 30 min
the oxidation was complete and allyl tributyltin (0.67 mL,
2.17 mmol) was added. The reaction was stirred for 1 h, then was
purified directly via flash chromatography (SiO2, pentane) to give
125.8, 122.3, 122.0, 110.2, 90.0, 31.9, 31.8, 29.4, 29.3, 29.2, 28.6, 22.7,
14.1; IR (neat) 3068, 2925, 2854, 1462, 1233, 1119, 1150, 1020, 960,
743 cmꢀ1; HRMS (ESI): m/z calcd for C17H25OS [MþH]þ 277.1548,
found 277.1602.
33 as a clear oil (232 mg, 90% yield):
d
1H NMR (400 MHz, CDCl3)
7.12 (dd, 1H, J¼7.6, 1.2 Hz), 6.99 (td, 1H, J¼7.6, 1.2 Hz), 6.87 (td, 1H,
J¼7.6, 0.8 Hz), 6.80 (dd,1H, J¼8.0, 0.8 Hz), 6.09 (t,1H, J¼6.4 Hz), 5.86
(ddt, 1H, J¼24.0, 10.0, 6.8 Hz), 5.23 (dd, 1H, J¼17.2, 1.2 Hz), 5.19 (dd,
1H, J¼10.0, 1.2 Hz), 2.85e2.92 (m, 1H), 2.70e2.77 (m, 1H); 13C NMR
4.8. 2-(Dec-1-yn-1-yl)benzo[d][1,3]oxathiole (37)
The general procedure for oxidative coupling was followed us-
ing 32 (200 mg, 1.45 mmol), LiClO4 (231 mg, 2.17 mmol), 4 A MS
ꢀ
d
(100 MHz, CDCl3) 155.9, 132.1, 126.0, 125.8, 122.5, 122.3, 119.4,
(200 mg), DDQ (395 mg, 1.74 mmol), and DCE (14 mL). The reaction
mixture was stirred for 30 min, then the potassium alkynyl tri-
fluoroborate (424 mg, 1.74 mmol) was added. The solution was
stirred for 1 h and then was purified directly via flash chromatog-
raphy (SiO2, pentane) to give 37 as a clear oil (258 mg, 65% yield). 1H
110.5, 89.7, 41.7; IR (neat) 3074, 2978, 2973, 2903, 1463, 1213,
745 cmꢀ1; HRMS (ESI): m/z calcd for C10H10OS [MþH]þ 179.0486,
found 179.0549.
4.5. 2-(Hept-1-en-3-yl)benzo[d][1,3]oxathiole (35)
NMR (400 MHz, CDCl3)
d
7.13 (d, 1H, J¼7.6 Hz), 7.02 (t, 1H, J¼7.6 Hz),
6.90 (t, 1H, J¼7.6 Hz), 6.84 (d, 1H, J¼8.0 Hz), 6.54 (s, 1H), 2.27 (t, 2H,
The general procedure for oxidative coupling was followed us-
J¼7.2 Hz), 1.53 (t, 2H, J¼7.6), 1.36 (m, 2H), 1.26 (s, 10H); 13C NMR
ing benzoxathiole 32 (100 mg, 0.723 mmol), LiClO4 (116 mg,
(100 MHz, CDCl3) d 154.8, 126.3, 125.7, 122.9, 122.2, 111.0, 90.9, 76.6,
ꢀ
1.09 mmol), 4 A MS (103 mg), DDQ (196 mg, 0.868 mmol), and DCE
76.0, 32.0, 29.3, 29.2, 29.0, 28.3, 22.8, 19.1, 14.3; IR (neat) 3069,
2926, 2855, 2239, 1462, 1247, 962, 743 cmꢀ1; HRMS (ESI): m/z calcd
for C17H22OS [M]þ 274.1391, found 274.1374.
(7 mL). The reaction mixture was stirred for 30 min, then (E)-hept-
2-en-1-yltrimethylsilane (148 mg, 0.868 mmol) was added. The
solution was stirred for 1 h, then was purified directly via flash
chromatography (SiO2, hexanes) to give 35 (3.1:1 dr) as a clear oil
4.9. 5-Bromo-2-phenylbenzo[d][1,3]oxathiole (39)
(122 mg, 72% yield). 1H NMR (400 MHz, CDCl3)
d
7.10 (dd, 1H, J¼7.6,
1.2 Hz), 6.97 (td, 1H, J¼7.6, 1.2 Hz), 6.84 (td, 1H, J¼7.6, 1.2 Hz), 6.77
(dd, 1H, J¼8.0, 0.8 Hz), 6.02 (d, 0.76H, J¼5.6 Hz), 5.99 (d, 0.26H,
J¼6.8 Hz), 5.61e5.71 (m, 1H), 5.14e5.23 (m, 2H), 2.54e2.64 (m, 1H),
1.58e1.68 (m,1H),1.30e145 (m, 5H), 0.89 (t, 3H, J¼6.9 Hz); 13C NMR
The general procedure for oxidative coupling was followed us-
ing benzoxathiole 38 (100 mg, 0.461 mmol), LiClO4 (74 mg,
ꢀ
0.69 mmol), 4 A MS (103 mg), DDQ (126 mg, 0.553 mmol), and DCE
(5 mL). The reaction mixture was stirred for 1 h at 50 ꢁC, then was
cooled to rt and potassium trifluorophenyl borate (102 mg,
0.553 mmol) was added. The reaction was stirred for 20 min and
then was purified directly via flash chromatography (SiO2, hexanes)
to give 39 as a clear oil (41 mg, 30% yield): 1H NMR (400 MHz,
(100 MHz, CDCl3)
d 156.1, 136.9, 125.6, 122.1, 121.9, 121.8, 118.4,
110.0, 93.4, 50.3, 29.6, 29.1, 22.6, 14.0; IR (neat) 3073, 2956, 2929,
2859, 1577, 1464, 1209, 1119, 920, 743 cmꢀ1; HRMS (ESI): m/z calcd
for C14H19OS [MþH]þ 235.1078, found 235.1150.
CDCl3)
d
7.79 (s, 2H), 7.63 (s, 2H), 7.48 (d, 2H, J¼7.2 Hz), 7.33 (dd, 1H,
4.6. 2-(Hept-1-en-3-yl)benzo[d][1,3]oxathiole (350)
J¼7.2, 1.2 Hz), 6.94 (m, 1H), 5.93 (s, 1H); 13C NMR (125 MHz, CDCl3)
d
155.6, 154.9, 137.8, 129.7, 128.9, 128.8, 126.6, 124.8, 235.5, 225.4,
The general procedure for oxidative coupling was followed us-
222.6, 91.2, 75.8; IR (neat) 3084, 2923, 2872, 1744, 1454, 1327, 1248,
1206, 1071, 999, 861, 740 cmꢀ1; HRMS (ESI): m/z calcd for
C13H9BrOS [M]þ 291.9557, found 291.9540.
ing benzoxathiole 32 (100 mg, 0.723 mmol), LiClO4 (116 mg,
ꢀ
1.09 mmol), 4 A MS (103 mg), DDQ (196 mg, 0.868 mmol), and DCE
(7 mL). The reaction mixture was stirred for 30 min, then (Z)-hept-
2-en-1-yltrimethylsilane (149 mg, 0.868 mmol) was added. The
solution was stirred for 1 h and then purified directly via flash
chromatography (SiO2, hexanes) to give 350 (1:4.6 dr) as a clear oil
4.10. 40-Methylene-40,50-dihydro-30H-spiro[benzo[d][1,3]ox-
athiole-2,20-furan] (43)
(112 mg, 66% yield): 1H NMR (400 MHz, CDCl3)
d
7.10 (d, 1H,
To a solution of 42 (150 mg, 0.535 mmol) in DCE (5 mL) was
added DDQ (292 mg, 1.28 mmol). The reaction mixture was stirred
for 10 min and then was purified directly by flash chromatography
(10% EtOAc in hexanes) to yield 43 as a colorless oil (91 mg, 82%
J¼7.6 Hz), 6.96 (t, 1H, J¼7.6 Hz), 6.84 (t, 1H, J¼7.6 Hz), 6.76 (d, 1H,
J¼8.0 Hz), 6.01 (d, 0.18H, J¼6.8 Hz), 5.99 (d, 0.82H, J¼6.8 Hz),
5.62e5.72 (m, 1H), 5.14e5.24 (m, 2H), 2.60e2.72 (m, 1H), 1.24e1.43
(m, 6H), 0.90 (t, 3H, J¼6.4 Hz); 13C NMR (100 MHz, CDCl3)
d
156.3,
yield): 1H NMR (400 MHz, CDCl3)
d
7.20 (d, 1H, J¼7.6 Hz), 7.05 (t, 1H,
136.6, 125.8, 125.6, 122.0, 121.8, 118.8, 110.0, 93.5, 50.5, 30.2, 29.1,
22.6, 14.0; IR (neat) 3073, 2956, 2929, 2859, 1762, 1577, 1464, 1209,
1119, 920, 743 cm-1; HRMS (ESI): m/z calcd for C14H19OS [MþH]þ
235.1078, found 235.1154.
J¼7.6 Hz), 6.94 (t, 1H, J¼7.6 Hz), 6.90 (d, 1H, J¼8.0 Hz), 5.17 (t, 1H,
J¼2.4 Hz), 5.07 (t, 1H, J¼2.4 Hz), 4.59e4.71 (m, 2H), 3.21e3.36 (m,
2H); 13C NMR (125 MHz, CDCl3)
d 153.1, 142.7, 125.7, 124.7, 124.4,
122.5, 121.7, 110.6, 106.7, 72.1, 44.5; IR (neat) 3070, 2930, 2873, 1577,
1463, 1424, 1277, 1240, 1170, 1019, 960, 874, 745 cmꢀ1; HRMS (ESI):
m/z calcd for C11H11O2S [MþH]þ 207.0402, found 207.0472.
4.7. (E)-2-(Dec-1-en-1-yl)benzo[d][1,3]oxathiole (36)
The general procedure for oxidative coupling was followed us-
4.11. 40-methylene-40,50-dihydro-30H-spiro[benzo[d][1,3]ox-
ing benzoxathiole 32 (100 mg, 0.723 mmol), LiClO4 (115 mg,
athiole-2,20-furan] (43)
ꢀ
1.09 mmol), 4 A MS (100 mg), DDQ (197 mg, 0.868 mmol), and DCE
(7 mL). The reaction mixture was stirred for 30 min, then potassium
(E)-dec-1-enyltrifluoroborate (214 mg, 0.868 mmol) was added.
The solution was stirred for 1 h and then purified directly via flash
chromatography (SiO2, hexanes) to give 36 as a clear oil (110 mg,
The general procedure for oxidative coupling was followed us-
ing benzoxathiole 32 (100 mg, 0.723 mmol), LiClO4 (115 mg,
ꢀ
1.09 mmol), 4 A MS (100 mg), DDQ (197 mg, 0.868 mmol), and DCE
(7 mL). The reaction mixture was stirred for 30 min, then nucleo-
phile 4427 (188 mg, 0.868 mmol) was added. The solution was
stirred for 1 h and then DDQ (199 mg, 0.876 mmol) was added. The
reaction mixture was stirred for 20 min followed by a third addition
of DDQ (101 mg, 0.438 mmol). The resulting solution was purified
directly via flash chromatography (SiO2, 10% EtOAc in hexanes) to
55% yield). 1H NMR (400 MHz, CDCl3)
d
7.11 (dd, 1H, J¼7.6, 1.2 Hz),
6.98 (td, 1H, J¼7.6, 1.2 Hz), 6.86 (td, 1H, J¼7.6, 1.2 Hz), 6.80 (dd, 1H,
J¼8.0, 0.8 Hz), 6.41 (d, 1H, J¼7.2 Hz), 5.81e5.96 (m, 2H), 2.09 (q, 2H,
6.0 Hz), 1.37e1.44 (m, 2H), 1.23e1.32 (m, 10H), 0.88 (t, 3H,
J¼7.2 Hz); 13C NMR (100 MHz, CDCl3)
d 155.6, 136.6, 126.6, 126.2,