4.25 (s, 2H), 2.35–2.20 (m, 1H), 2.26–2.07 (m, 4H), 1.83–1.74
(m, 1H), 1.78 (t, 3H, J = 2.5 Hz), 1.65 (s, 3H), 1.62–1.52
(m, 2H); 13C NMR δ 145.7, 112.4, 86.2, 78.4, 77.3, 76.8, 51.4,
45.5, 30.9, 23.6, 18.9, 16.7, 3.5; MS (DART) m/z 191 (M+ + 1,
79.9); HRMS (DART) calcd for C13H19O 191.1436, found
191.1424.
J = 3.0 Hz), 2.28–2.22 (m, 1H), 2.20–2.15 (m, 2H), 2.02–1.83
(m, 2H), 1.77 (t, 3H, J = 2.3 Hz), 1.75–1.66 (m, 1H), 1.64
(s, 3H), 1.55–1.45 (m, 2H); 13C NMR δ 204.2, 146.4, 112.0,
104.5, 78.8, 77.6, 76.5, 62.9, 46.0, 29.7, 26.3, 23.8, 18.8, 3.5;
MS (DART) m/z 205 (M+ + 1, 8.3); HRMS (DART) calcd for
C14H21O 205.1592, found 205.1589.
(+)-(R)-6-Isopropenyl-1-methoxycarbonyloxy-2,8-decadiyne (12)
(+)-(R)-3-(tert-Butyldimethylsilyloxy)-6-isopropenyl-1,2-
To a solution of (+)-11 (411 mg, 2.16 mmol) in CH2Cl2 (10 mL)
were added pyridine (1.0 mL, 13 mmol) and ClCO2Me
(0.50 mL, 6.5 mmol) at 0 °C. The reaction mixture was stirred
for 15 min at the same temperature. Then the reaction was
quenched by addition of saturated aqueous NaHCO3, and the
mixture was extracted with CH2Cl2. The extract was washed
with water and brine, dried, and concentrated to dryness. Chrom-
atography of the residue with hexane–AcOEt (20 : 1) afforded
(+)-12 (536 mg, quant.) as a colorless oil; [α]2D7 +27.6 (c 0.10,
decadien-8-yne (18)
To a solution of (+)-16 (120 mg, 0.590 mmol) in CH2Cl2 (6 mL)
were added TBSCl (134 mg, 0.886 mmol) and Et3N (0.25 mL,
1.8 mmol) and DMAP (3.6 mg, 0.030 mmol) at 0 °C. The reac-
tion mixture was stirred for 13 h at room temperature. Then the
reaction was quenched by addition of water, and the mixture was
extracted with CH2Cl2. The extract was washed with water and
brine, dried, and concentrated to dryness. Chromatography of the
residue with hexane afforded (+)-18 (170 mg, 91%) as a color-
CHCl3); IR 1751 cm−1 1H NMR δ 4.85–4.82 (m, 1H),
;
less oil; [α]D22 +2.7 (c 1.0, CHCl3); IR 1958 cm−1 1H NMR
;
4.78–4.76 (m, 1H), 4.72 (t, 2H, J = 2.3 Hz), 3.80 (s, 3H),
2.33–2.22 (m, 1H), 2.21–2.06 (m, 4H), 1.77 (t, 3H, J = 2.5 Hz),
1.82–1.74 (m, 1H), 1.64 (s, 3H), 1.61–1.51 (m, 1H);
13C NMR δ 155.3, 145.6, 112.4, 88.1, 77.2, 76.8, 73.5, 56.2,
55.0, 45.5, 30.7, 23.6, 18.9, 16.7, 3.5; MS (DART) m/z 249 (M+
+ 1, 10.2); HRMS (DART) calcd for C15H21O3 249.1491, found
249.1484.
δ 4.80–4.79 (m, 1H), 4.75–4.72 (m, 3H), 4.12 (t, 2H, J = 2.3
Hz), 2.28–2.22 (m, 1H), 2.20–2.17 (m, 2H), 2.02–1.92 (m, 1H),
1.91–1.83 (m, 1H), 1.77 (t, 3H, J = 2.5 Hz), 1.72–1.66 (m, 1H),
1.64 (s, 3H), 1.54–1.42 (m, 1H), 0.89 (s, 9H), 0.06 (s, 6H);
13C NMR δ 205.7, 146.9, 112.2, 103.8, 78.1, 76.74, 76.70, 64.6,
46.5, 30.1, 26.4, 26.2, 24.1, 19.1, 18.7, 3.8, −5.0; MS (DART)
m/z 319 (M+ + 1, 10.5); HRMS (DART) calcd for C20H35OSi
319.2457, found 319.2473.
(+)-(R)-6-Isopropenyl-3-methoxycarbonyl-1,2-decadien-8-yne (13)
To a solution of (+)-12 (57.4 mg, 0.231 mmol) in MeOH
(1.0 mL) were added Pd(OAc)2 (2.6 mg, 0.012 mmol) and PPh3
(12 mg, 0.046 mmol) at room temperature. The reaction mixture
was warmed to 40 °C under CO (10 atm) and stirred for 24 h.
Then MeOH was evaporated off, and the residue was chromato-
graphed with hexane–AcOEt (80 : 1) to afford (+)-13 (38 mg,
71%) as a colorless oil; [α]2D3 +7.0 (c 1.6, CHCl3); IR 1965,
(+)-Indicanone (1)
To a solution of (+)-18 (14.7 mg, 0.0462 mmol) in toluene
(1.0 mL) was added [RhCl(CO)dppp]2 (3.0 mg, 2.6 × 10−3
mmol) at room temperature, and reaction mixture was warmed to
refluxed under CO (1 atm) and stirred for 3 h. Then 10%
aqueous HCl (0.5 mL) and MeOH (1 mL) was added to the reac-
tion mixture, which was stirred for an additional 1 h at room
temperature. The reaction was quenched by addition of saturated
aqueous NaHCO3, and the mixture was extracted with AcOEt.
The extract was washed with water and brine, dried, and concen-
trated to dryness. Chromatography of the residue with hexane–
AcOEt (1 : 1) afforded (+)-indicanone (1) (10.2 mg, 95%) as a
colorless oil; [α]2D3 +16.6 (c 0.73, MeOH); IR 3607, 3420,
1936, 1713 cm−1 1H NMR δ 5.14 (t, 2H, J = 3.2 Hz),
;
4.83–4.79 (m, 1H), 4.75 (brs, 1H), 3.74 (s, 3H), 2.27–2.16
(m, 4H), 2.15–2.07 (m, 1H), 1.76 (t, 3H, J = 2.3 Hz), 1.72–1.63
(m, 1H), 1.65 (s, 3H), 1.55–1.46 (m, 1H); 13C NMR
δ 213.8, 167.6, 146.2, 112.2, 100.0, 79.1, 77.6, 76.5, 52.2,
46.0, 30.3, 25.8, 23.8, 18.8, 3.5; MS (DART) m/z 233 (M+ + 1,
100); HRMS (DART) calcd for C15H21O2 233.1542, found
233.1559.
1
1682 cm−1; H NMR δ 4.74 (s, 2H), 4.20 (s, 2H), 2.99 (s, 2H),
2.82 (dd, 1H, J = 15.5, 4.1 Hz), 2.73 (dd, 1H, J = 15.3, 8.9 Hz),
2.64 (ddd, 1H, J = 15.5, 8.4, 2.8 Hz), 2.55–2.44 (m, 2H),
2.05–1.97 (m, 2H), 1.80 (s, 3H), 1.84–1.77 (m, 1H), 1.77 (s,
3H); 1H NMR (acetone-d6) δ 4.74 (br s, 1H), 4.69 (quin, 1H, J =
1.3 Hz), 4.11, 4.08 (ABq, 2H, JAB = 12.7 Hz), 2.95, 2.91 (ABq,
2H, JAB = 20.6 Hz), 2.83 (dd, 1H, J = 15.4, 4.4 Hz), 2.77
(dd, 1H, J = 15.4, 8.5 Hz), 2.63 (ddd, 1H, J = 16.7, 8.5, 2.7 Hz),
2.54–2.45 (m, 2H), 1.99–1.94 (m, 1H), 1.78–1.71 (m, 4H), 1.70
(s, 3H); 13C NMR δ 204.3, 167.1, 149.3, 140.2, 137.6, 133.9,
109.7, 65.7, 43.0, 39.0, 33.5, 32.4, 28.7, 20.5, 8.5; 13C NMR
(acetone-d6) δ 203.5, 167.1, 150.6, 139.8, 139.5, 133.4, 109.7,
65.2, 43.9, 39.2, 33.9, 33.2, 28.9, 20.5, 8.3; MS (DART) m/z
233 (M+ + 1, 100); HRMS (DART) calcd for C15H21O2
233.1542, found 233.1526.
(+)-(R)-6-Isopropenyl-3-hydroxymethyl-1,2-decadien-8-yne (16)
To a solution of (+)-13 (116 mg, 0.500 mmol) in toluene
(5.0 mL) was added DIBAL-H (1.0 M in toluene, 1.5 mL,
1.5 mmol) at −78 °C. The reaction mixture was stirred for 4 h at
the same temperature. Then the reaction was quenched by
addition of MeOH and saturated sodium potassium tartrate
(Rochelle’s salt), and the mixture was extracted with AcOEt. The
extract was washed with water and brine, dried, and concentrated
to dryness. Chromatography of the residue with hexane–AcOEt
(10 : 1) afforded (+)-16 (87 mg, 85%) as a colorless oil; [α]D26
+7.9 (c 0.52, CHCl3); IR 3605, 3450, 1958 cm−1 1H NMR
;
δ 4.90–4.87 (m, 2H), 4.80 (brs, 1H), 4.74 (brs, 1H), 4.04 (t, 2H,
4750 | Org. Biomol. Chem., 2012, 10, 4747–4751
This journal is © The Royal Society of Chemistry 2012