9026
A.S.K. Hashmi, M. Wo¨lfle / Tetrahedron 65 (2009) 9021–9029
6.30 (dd, J¼3.2, 1.9 Hz, 1H), 7.26–7.79 (m, 1H), 7.32–7.37 (m, 5H).
C12H12O2 (188.22): calcd C 76.57, H 6.43; found C 76.48, H 6.55.15
To a solution of the alcohol 4c (1.79 g, 9.48 mmol) in DCM
(60 mL) was added DMP (4.42 g, 10.4 mmol). Column chromato-
graphy (silica gel, PE/EA, 2:1) afforded 1.22 g (6.60 mmol, 70%) of 5c
as yellow acicular crystals. Rf (PE/EA, 10:1)¼0.23. 1H NMR (CDCl3,
(d), 108.66 (d), 148.81 (s), 151.59 (s). MS (ESI): m/z (%): 173 (100)
[MþNa]þ, 149 (44), 133 (90), 105 (88), 103 (46). HRMS (ESI):
[C9H10O2þNa]þ: calcd 173.0573, found 173.0572.
500 MHz):
d
¼4.30 (s, 2H), 6.24 (ddt, J¼3.2, 0.9, 0.8 Hz, 1H), 6.33 (dd,
O
OH
J¼3.2,1.9 Hz,1H), 7.37 (d, J¼1.90 Hz, 0.90 Hz,1H), 7.44–7.48 (m, 2H),
7.55–7.58 (m, 1H), 7.99–8.02 (m, 2H).16
6e
To a solution of ethynylmagnesium chloride (14.6 mL, 0.6 M
solution in THF/toluene, 8.75 mmol) in THF (60 mL) was added
a solution of 5c (858 mg, 4.61 mmol) in THF (30 mL). Purification by
column chromatography (silica gel, PE/EA, 10:1) afforded an orange
oil of 6c (282 mg, 1.33 mmol, 28%). Rf (PE/EA, 10:1)¼0.30. IR (neat):
4.1.5. 2-Methyl-1-(5-methylfuran-2-yl)but-3-yn-2-ol (6e). According
to the general procedure of the preparation of
b-ethynyl-b-
hydroxyfurans 2-methylfuran (2.00 g, 24.4 mmol) was dissolved in
THF (20 mL) and deprotonated with n-BuLi (16.0 mL, 1.6 M solution
in hexane, 25.6 mmol). Then propylene oxide (1.41 g, 24.4 mmol)
was added dropwise and the mixture stirred for 2 d. Purification by
column chromatography (silica gel, PE/EA, 4:1) afforded 4e (2.82 g,
20.1 mmol, 82%) as a yellow liquid. Rf (PE/EA, 4:1)¼0.23. 1H NMR:
n
¼3540 cmꢁ1, 3288, 1501, 1448, 1146, 1011, 670. 1H NMR (CDCl3,
500 MHz):
d
¼2.66 (s, 1H), 2.87 (br s, 1H), 3.25 (s, 1H), 6.15 (ddt,
J¼3.2, 0.8, 0.8 Hz, 1H), 6.32 (dd, J¼3.2, 1.9 Hz, 1H), 7.29–7.33 (m, 1H),
7.35–7.38 (m, 3H), 7.61–7.64 (m, 2H). 13C NMR (CDCl3, 126 MHz):
(CDCl3, 300 MHz):
d
¼1.24 (d, J¼6.2 Hz, 3H), 1.86–1.88 (m, 1OH),
d
¼44.29 (t), 72.24 (d), 74.58 (s), 85.39 (s), 108.89 (d), 110.41 (d),
2.26 (s, 3H), 2.66 (dd, J¼14.8, 7.8 Hz, 1H), 2.77 (dd, J¼14.8, 4.4 Hz,
1H), 4.00–4.12 (m, 1H), 5.86–5.89 (m, 1H), 5.98 (d, J¼3.0 Hz, 1H).
C8H12O2 (140.18).
125.28 (d, 2C), 127.99 (d), 128.23 (d, 2C), 142.06 (d), 143.04 (s),
150.45 (s). MS (EI, 70 eV): m/z (%): (7) [M]þ, 131 (88), 82 (100), 53
(53). MS (ESI): m/z (%): 235 (100) [MþNa]þ. HRMS (ESI):
[C14H12O2þNa]þ: calcd 235.0730, found 235.0726.
To a solution of the alcohol 4e (1.00 g, 7.13 mmol) in DCM
(40 mL) was added DMP (3.33 g, 7.85 mmol). Column chromato-
graphy (silica gel, PE/EA, 6:1) afforded 905 mg (6.55 mmol, 92%) of
the ketone 5e as a yellow liquid. Rf (PE/EA, 6:1)¼0.28. 1H NMR:
HO
(CDCl3, 300 MHz):
(m, 1H), 6.06 (d, J¼3.0 Hz, 1H). C8H10O2 (138.16).
d
¼2.17 (s, 3H), 2.27 (s, 3H), 3.65 (s, 2H), 5.91–5.93
O
6d
To a solution of ethynylmagnesium chloride (13.0 mL, 0.6 M
solution in THF/toluene, 7.78 mmol) in THF (20 mL) was added
a solution of 5e (895 mg, 6.48 mmol) in THF (20 mL). Purification by
column chromatography (silica gel, PE/EA, 8:1) afforded a yellow
liquid of 6e (600 mg, 3.65 mmol, 57%). Rf (PE/EA, 8:1)¼0.13. IR
4.1.4. 1-(5-Methylfuran-2-yl)but-3-yn-2-ol (6d). According to the
general procedure of the preparation of b-ethynyl-b-hydroxyfurans
2-methylfuran (10.0 g, 122 mmol) was dissolved in THF (100 mL)
and deprotonated with n-BuLi (76.1 mL, 1.6 M solution in hexane,
122 mmol). Then ethylene oxide (5.37 g, 122 mmol) was condensed
by an acetone/dry ice condenser into the solution and stirred for 8 h
at room temperature. Fractional vacuum distillation (bp 69 ꢀC,
1 mbar) afforded the alcohol 4d (10.5 g, 83.3 mmol, 68%) as a col-
(neat):
n
¼3373 cmꢁ1, 3290, 2985, 2929, 1563, 1365, 1208, 1114,
1068, 938, 788, 643. 1H NMR (CDCl3, 500 MHz):
d¼1.54 (s, 3H), 2.27
(d, J¼1.0 Hz, 3H), 2.43 (s, 1H), 2.51 (br s, 1H), 2.95 (d, J¼14.8 Hz, 1H),
3.02 (d, J¼14.8 Hz, 1H), 5.91 (dq, J¼3.0, 1.0 Hz, 1H), 6.11 (d, J¼3.0 Hz,
1H). 13C NMR (CDCl3, 126 MHz):
d¼13.61 (q), 29.12 (q), 42.16 (t),
ourless liquid. Bp 69 ꢀC (1 mbar). IR (neat):
n
¼3324 cmꢁ1, 2921,
67.24 (s), 71.64 (d), 86.92 (s), 106.30 (d), 109.36 (d), 149.00 (s),
151.69 (s). MS (ESI): m/z (%): 187 (100) [MþNa]þ. HRMS (ESI):
[C10H12O2þNa]þ: calcd 187.0730, found 187.0737.
2884, 1569, 1443, 1218, 1044, 783, 648. 1H NMR (500 MHz, CDCl3):
d
¼1.68 (br s, 1H), 2.25 (d, J¼1.0 Hz, 1H), 2.84 (t, J¼6.2 Hz, 2H), 3.84
(t, J¼6.2, 2H), 5.86 (dq, J¼3.0, 1.0 Hz, 1H), 5.97 (d, J¼3.0 Hz, 1H). 13C
NMR (62.9 MHz, CDCl3):
d
¼13.65 (q), 31.78 (t), 61.33 (t), 106.17 (d),
107.40 (d), 150.96 (s), 151.26 (s). MS (EI, 70 eV): m/z (%): 126 (21)
[M]þ, 95 (100), 43 (15). HRMS (EI): C7H10O2: calcd 126.0681, found
126.0681.
Ph
O
OH
To a solution of the alcohol 4d (500 mg, 3.96 mmol) in DCM
(30 mL) was added DMP (1.86 g, 4.36 mmol). Column chromato-
graphy (silica gel, PE/EA, 10:1) afforded 334 mg (2.68 mmol, 68%) of
5d as a yellow, volatile liquid. Rf (PE/EA, 10:1)¼0.18. IR (neat):
6f
4.1.6. 1-(5-Methylfuran-2-yl)-2-phenylbut-3-yn-2-ol (6f). According
to the general procedure of the preparation of b-ethynyl-b-
n
¼2922 cmꢁ1, 2928, 2730, 1726, 1566, 1388, 1219, 1022, 942, 785,
618. 1H NMR (CDCl3, 250 MHz):
d
¼2.27–2.28 (m, 3H), 3.64–3.66 (m,
hydroxyfurans 2-methylfuran (2.00 g, 24.4 mmol) was dissolved in
THF (40 mL) and deprotonated with n-BuLi (16.0 mL, 1.6 M solution
in hexane, 25.6 mmol). Then styrene oxide (2.79 mL, 2.93 g,
24.4 mmol) was added dropwise and the mixture stirred for 2 d.
Purification by column chromatography (silica gel, PE/EA, 10:1)
afforded 4f (1.50 g, 7.42 mmol, 32%) as a yellow oil. Rf (PE/EA,
2H), 5.93–5.95 (m, 1H), 6.11 (d, J¼3.0 Hz, 1H), 9.70 (t, J¼2.3 Hz, 1H).
13C NMR (CDCl3, 63 MHz):
d
¼13.49 (q), 42.98 (t), 106.62 (d), 109.52
(d), 144.30 (s), 152.43 (s), 197.26 (s). MS (ESI): m/z (%): 125 (67)
[MþH]þ, 123 (79), 109 (79), 95 (100). HRMS (ESI): [C7H8O2þH]þ:
calcd 125.0597, found 125.0594.
To a solution of ethynylmagnesium chloride (6.22 mL, 0.6 M
solution in THF/toluene, 3.73 mmol) in Et2O (20 mL) was added 5d
(858 mg, 4.61 mmol). Purification by column chromatography
(silica gel, PE/EA, 6:1) afforded a yellowish liquid of 6d (232 mg,
10:1)¼0.14. 1H NMR: (CDCl3, 300 MHz):
¼2.27–2.28 (m, 3HþOH),
d
2.90–3.04 (m, 2H), 4.94–4.99 (m, 1H), 5.88 (d, J¼3.0 Hz, 1H), 5.97 (d,
J¼3.0 Hz, 1H), 7.26–7.41 (m, 5H).
To a solution of the alcohol 4f (1.50 g, 7.42 mmol) in DCM
(50 mL) was added DMP (3.46 g, 8.16 mmol). Column chromatog-
raphy (silica gel, PE/EA, 10:1) afforded 1.46 g (7.29 mmol, 98%) of
the ketone 5f as a yellow oil. Rf (PE/EA, 4:1)¼0.42. 1H NMR: (CDCl3,
1.54 mmol, 62%). Rf (PE/EA, 6:1)¼0.17. IR (neat):
n
¼3283 cmꢁ1, 1711,
1568, 1217, 1030, 787, 657. 1H NMR (CDCl3, 250 MHz):
d
¼2.22 (br d,
J¼5.1 Hz, 1H), 2.26–2.27 (m, 3H), 2.47 (d, J¼2.1 Hz, 1H), 2.97 (dd,
J¼14.9, 6.8 Hz, 1H), 3.05 (dd, J¼14.9, 5.6 Hz, 1H), 4.59–4.67 (m), 5.89
(dq, J¼3.0, 1.1 Hz, 1H), 6.07 (d, J¼3.0 Hz, 1H). 13C NMR (CDCl3,
300 MHz):
d
¼2.26 (s, 3H), 4.26 (s, 2H), 5.91 (d, J¼3.0 Hz, 1H), 6.09
(d, J¼3.0 Hz, 1H), 7.43–7.51 (m, 2H), 7.54–7.61 (m, 1H), 7.99–8.04
63 MHz):
d
¼13.55 (q), 36.70 (t), 61.12 (d), 73.35 (d), 83.81 (s),106.25
(m, 2H).