A. Erkkilä, P. M. Pihko
FULL PAPER
NaHCO
3ϫ5 mL). The combined organic extracts were then washed with
brine, dried (Na SO ), and concentrated in vacuo. For the isolation
of 10f, the reaction mixture was added to H O (5 mL) and the
resulting mixture extracted with CH Cl (3ϫ5 mL). The combined
organic extracts were then washed with 7% NaHCO (5 mL), brine,
dried (Na SO ), and concentrated in vacuo.
3
(5 mL) and the resulting mixture extracted with CH
2
Cl
2
6.25 (m, 1 H), 6.01 (m, 1 H), 5.60–5.52 (m, 1 H), 5.45–5.35 (m, 1
H), 2.98 (dd, J = 1.1, 7.4 Hz, 2 H), 2.02 (dq, J = 1.1, 6.8 Hz, 2 H),
(
1
3
2
4
1.39–1.24 (m, 6 H), 0.88 (t, J = 6.8 Hz, 3 H) ppm. C NMR
(CHCl , 100 MHz): δ = 194.4, 149.0, 134.0, 133.0, 124.4, 31.5, 29.2,
2
3
2
2
27.1, 25.5, 22.5, 14.0 ppm. HRMS (ESI+): calcd. for [C11
Na] 189.1255; found 189.1265.
H18O +
3
2
4
Methyl (E)-6-Formylhepta-2,6-dienoate (10i): Yield 171.6 mg
(quant). IR: ν˜ max = 3154, 2993, 2925, 2848, 1793, 1719, 1690, 1438,
(
S)-3,7-Dimethyl-2-methyleneoct-6-enal (10a): Yield 170.1 mg
1
–1 1
(quant.). H NMR (CDCl
3
, 400 MHz): δ = 9.53 (s, 1 H); 6.23 (s, 1
1282, 1207, 910, 734, 650 cm . H NMR (CDCl3, 400 MHz): δ =
H); 5.98 (s, 1 H); 5.07 (tt, J = 1.2, 7.2 Hz, 1 H); 2.70 (sext, J = 9.53 (s, 1 H), 6.91 (dt, J = 6.6, 15.7 Hz, 1 H), 6.27 (s, 1 H), 6.05 (s,
.8 Hz, 1 H); 1.92 (m, 2 H); 1.67 (s, 3 H); 1.56 (s, 3 H); 1.51 (m, 1
1 H), 5.82 (dt, J = 1.5, 15.7 Hz, 1 H), 3.71 (s, 3 H), 2.43–2.35 (m,
6
1
3
13
H); 1.37 (m, 1 H); 1.06 (d, J = 6.8 Hz, 3 H) ppm. C NMR 4 H) ppm. C NMR (CHCl
CDCl , 100 MHz): δ = 194.7; 155.5; 133.2, 131.5, 124.1; 35.6; 30.9;
147.6, 134.8, 121.7, 51.4, 30.0, 26.5 ppm. HRMS (ES+): calcd. for
5.7; 25.6; 19.5; 17.6 ppm. The spectroscopic data match those re-
[C + Na] 191.0684; found 191.0675.
3
, 100 MHz): δ = 194.2, 166.8, 148.5,
(
2
3
9 12 3
H O
[25]
ported in the literature.
-Benzylacrylaldehyde (10b): Yield 165.8 mg (99%). 1H NMR
CDCl
1
tert-Butyl 1-Formylvinylcarbamate (10j): Yield 83.6 mg (98%). H
NMR (CDCl , 400 MHz): δ = 9.12 (s, 1 H); 6.97 (s, 1 H); 6.70 (s,
2
(
3
1
3
3
, 400 MHz): δ = 9.61 (s, 1 H); 7.32–7.17 (m, 5 H); 6.11 (s, 1 H); 5.35 (s, 1 H); 1.46 (s, 9 H) ppm. C NMR (CDCl ,
3
H); 6.07 (s, 1 H); 3.57 (s, 2 H) ppm. 1 C NMR (CDCl
3
100 MHz): δ = 188.6, 152.3, 140.2, 114.8, 81.0, 28.1 ppm. The spec-
1
1
3
,
troscopic data match those reported in the literature.[
27]
00 MHz): δ = 193.9, 149.7, 138.1, 135.2, 129.1, 128.5, 126.4, 34.1
ppm. The spectroscopic data match those reported in the litera-
General Procedure for the Preparative Self-Sondensations of Alde-
hydes: To a solution of amine 3a (8.5 µL, 0.1 mmol, 10 mol-%) and
acid 4a (33.0 mg, 0.2 mmol, 20 mol-%) in dichloromethane
ture.[
26]
3,3-Dimethyl-2-methylenebutanal (10c): Yield 95.6 mg (85%). IR:
(
1.0 mL), was added aldehyde 1 (2.0 mmol, 200 mol-%) at room
ν˜ max = 3380, 2961, 2872, 1702, 1460, 1364, 1306, 1195, 953, 848,
–
1
1
temp. The reaction mixture was rapidly heated to 45 °C and stirred
for the indicated period of time. The reaction mixture was then
6
1
1
70 cm . H NMR (CDCl
3
, 400 MHz): δ = 9.54 (s, 1 H); 6.30 (s,
H); 5.90 (s, 1 H); 1.19 (s, 9 H) ppm. 1 C NMR (CDCl
3
3
,
added to 7% NaHCO
with CH Cl (3ϫ5 mL). The combined organic extracts were then
washed with brine, dried (Na
3
(5 mL) and the resulting mixture extracted
00 MHz): δ = 195.0, 158.1, 133.6, 33.8, 28.5 ppm. HRMS (ESI+):
12O + H] 113.0966; found 133.0931.
calcd. for [C
7
H
2
2
2
4
SO ), and concentrated in vacuo.
2
-Methylene-3-phenylbutanal (10d): Yield 161.2 mg (quant.). IR:
1
–
1
(E)-2-Methylpent-2-enal (11k): H NMR (CDCl
3
, 400 MHz): δ =
ν˜ max = 2986, 2305, 1693, 1421, 1265, 950, 896, 741, 705, 409 cm .
1
9.30 (s, 1 H), 6.47 (tq, J = 1.3, 7.4 Hz, 1 H), 2.36 (ddq, J = 0.9,
.4, 7.4 Hz, 2 H), 1.72 (dt, J = 0.9, 1.3 Hz, 3 H), 1.11 (t, J = 7.4 Hz,
H NMR (CDCl
3
, 400 MHz): δ = 9.54 (s, 1 H); 7.33–7.16 (m, 5
7
H); 6.24 (s, 1 H); 6.08 (s, 1 H); 4.06 (q, J = 7.2 Hz, 1 H); 1.43 (d,
1
3
J = 7.2 Hz, 3 H) ppm. 1 C NMR (CDCl
54.4, 143.6, 133.6, 128.4, 127.5, 126.4, 37.2, 20.0 ppm. HRMS
ESI+): calcd. for [C11 12O + H] 183.0786; found 183.0765.
-(Benzyloxy)acrylaldehyde (10e): Yield 171.5 mg (quant.). 1H
3
3 H) ppm. C NMR (CHCl
3
, 100 MHz): δ = 195.4, 156.2, 138.8,
3
, 100 MHz): δ = 193.8,
2
2.3, 12.8, 9.0 ppm. These spectroscopic data match those reported
1
[28]
in the literature.
(
H
(E)-2-Benzyl-5-phenylpent-2-enal (11b): Yield 122.2 mg (98%). IR:
ν˜ max = 3027, 2924, 1683, 1639, 1601, 1495, 1453, 1075, 912, 735,
2
NMR (CDCl
3
, 400 MHz): δ = 9.30 (s, 1 H); 7.38–7.30 (m, 5 H);
–
1 1
6
98 cm . H NMR (CDCl
3
, 400 MHz): δ = 9.49 (s, 1 H), 7.36–
5
.25 (d, J = 3.0 Hz, 1 H); 5.14 (d, J = 3.0 Hz, 1 H); 4.93 (s, 2 H)
13
7.13 (m, 10 H), 6.66 (t, J = 7.1 Hz, 1 H), 3.63 (s, 2 H), 2.84–2.74
ppm. C NMR (CDCl
3
, 100 MHz): δ = 188.0, 158.1, 135.5, 128.6,
1
3
(
m 4 H) ppm. C NMR (CHCl
142.7, 140.4, 140.0, 128.5, 128.4, 128.3, 128.2, 126.3, 126.0, 34.4,
1.0, 29.6 ppm. HRMS (ES+): calcd. for [C18 18O + Na] 251.1436;
found 251.1446.
3
, 100 MHz): δ = 194.5, 154.7,
1
28.1, 127.3, 103.8, 70.1 ppm. The spectroscopic data match those
[6b]
reported in the literature.
-[(Benzyloxy)methyl]acrylaldehyde (10f): Yield 150.1 mg (85%).
IR: ν˜ max = 3436, 3088, 3064, 3031, 2863, 1954, 1693, 1496, 1454,
3
H
2
(
Z)-2,4-Bis(benzyloxy)but-2-enal (11e): Yield 116.7 mg (40%). IR:
–1 1
1368, 1101, 960, 739 cm . H NMR (CDCl
3
, 400 MHz): δ = 9.60
ν˜ max = 3033, 2857, 1694, 1644, 1496, 1454, 1322, 1179, 1100, 1026,
(
s, 1 H); 7.38–7.28 (m, 5 H); 6.58 (s, 1 H); 6.16 (d, J = 1.6 Hz, 1
–
1 1
9
11, 732, 697 cm . H NMR (CDCl
3
, 400 MHz): δ = 9.31 (s, 1 H),
13
3
H); 4.59 (s, 2 H), 4.26 (t, J = 1.6 Hz, 2 H) ppm. C NMR (CDCl ,
7
.45–7.22 (m, 10 H), 6.13 (t, J = 6.0 Hz, 1 H), 5.13 (s, 2 H), 4.48
1
6
00 MHz): δ = 193.3, 146.7, 137.8, 134.0, 128.4, 127.7, 127.6, 73.0,
5.8 ppm. HRMS (ESI+): calcd. for [C11 + Na] 199.0735;
1
3
(
3
s, 2 H), 4.29 (d, J = 6.0 Hz, 2 H) ppm. C NMR (CHCl ,
12 2
H O
1
1
00 MHz): δ = 188.7, 153.3, 137.5, 136.7, 135.9, 128.4, 128.3 (2 C),
28.2, 127.8, 127.7, 72.9, 72.8, 64.6 ppm. HRMS (ES+): calcd. for
found 199.0732.
-Methylene-3-(5-methylfuran-2-yl)butanal (10g): Yield 164.9 mg
quant.). IR: ν˜ max = 2976, 2923, 1693, 1627, 1565, 1455, 1359, 1219,
2
18 18 3
[C H O + Na] 305.1154; found 305.1156.
(
1
(
2E,6Z)-2-[(Z)-Oct-2-enyl]dodeca-2,6-dienal (11h): Yield 132.3 mg
–1 1
3
022, 954, 784 cm . H NMR (CDCl , 400 MHz): δ = 9.58 (s, 1
(
1
91%). IR: ν˜ max = 3009, 2956, 2926, 2856, 1688, 1640, 1456, 1377,
156, 913, 734 cm . H NMR (CDCl , 400 MHz): δ = 9.27 (s, 1
3
H), 6.18 (d, J = 0.8 Hz, 1 H), 6.05 (s, 1 H), 5.59 (d, J = 3.0 Hz, 1
H), 5.85 (dd, J = 1.0, 3.0 Hz, 1 H), 4.04 (q, J = 7.2 Hz, 1 H), 2.23
–
1 1
H), 6.46 (t, J = 7.3 Hz, 1 H), 5.48–5.28 (m, 3 H), 5.21–5.14 (m, 1
H), 3.00 (d, J = 2 H, 7.1 Hz), 2.45 (q, J = 7.4 Hz, 2 H), 2.23 (q, J
13
(
3
br. s, 3 H), 1.37 (d, J = 7.2 Hz, 3 H) ppm. C NMR (CHCl ,
1
1
00 MHz): δ = 193.4, 154.7, 152.5, 150.9, 134.2, 106.1, 105.8, 31.1,
8.2, 13.4 ppm. HRMS (ES+): calcd. for [C10 + H] 164.0837;
=
7.2 Hz, 2 H), 2.11 (q, J = 7.1 Hz, 2 H), 2.02 (q, J = 6.8 Hz, 2 H),
12 2
H O
1
3
1.40–1.18 (m, 12 H), 0.93–0.82 (m, 3 H) ppm. C NMR (CHCl
3
,
found 164.0735.
Z)-2-Methylenedec-4-enal (10h): Yield 170.1 mg (quant.). IR: ν˜ max
3583, 3367, 3011, 2927, 2857, 1691, 1638, 1466, 1437, 1377, 1234,
100 MHz): δ = 194.5, 154.5, 142.8, 131.7, 131.0, 127.5, 125.7, 31.6,
(
31.5, 29.3, 29.2, 29.1, 27.2 (2 C), 26.1, 22.6, 22.5, 22.3, 14.0 (2 C)
=
ppm. HRMS (ES+): calcd. for [C20
291.2694.
H34O + Na] 291.2688; found
–1 1
959, 861, 717 cm . H NMR (CDCl
3
, 400 MHz): δ = 9.59 (s, 1 H),
4214
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Eur. J. Org. Chem. 2007, 4205–4216