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New Journal of Chemistry
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1): 3479, 3004, 2956, 2860, 1789, 1733, 1637, 1476, 1286, 1202, 2,2-Dimethyl-5-(Z)-(octadec-9-enylidene)-1,3-dioxane-4,6-dione
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DOI: 10.1039/D0NJ02263B
1001, 912, 799.
(9h). Yield 81%. Yellow liquid. H NMR (300 MHz, CDCl3): 0.89 (t,
3H, J = 6.0 Hz), 1.28 (m, 20H), 1.60 (m, 2H), 1.74 (s, 6H), 2.01 (m, 4H),
2.95 (m, 2H), 5.36 (m, 2H), 7.94 (t, 1H, J = 6.0 Hz). 13C NMR (75 MHz,
CDCl3): 14.1, 22.6, 27.1(2C), 27.5, 27.6, 28.0, 28.1, 29.1(2C), 29.3,
29.4(2C), 29.6(2C), 29.7, 31.8, 104.8, 105.7, 129.7, 130.0, 159.8,
165.4, 169.0. IR max, cm-1): 3004, 2924, 2844, 1741, 1620, 1467,
1274, 1202, 1017, 792, 719.
2,2-Dimethyl-5-(hexylidene)-1,3-dioxane-4,6-dione (9b). Yield 95%.
Yellow liquid. 1H NMR (300 MHz, CDCl3): 0.92 (t, 3H, J = 6.0 Hz), 1.38
(m, 4H), 1.62 (m, 2H), 1.76 (s, 6H), 2.96 (q, 2H, J = 7.5 Hz), 7.95 (t, 1H,
J = 7.5 Hz). 13C NMR (75 MHz, CDCl3): 14.7, 23.2, 28.3, 29.5, 31.7,
32.3, 105.4, 118.6, 160.4, 162.5, 165.6, 169.6. IR max, cm-1): 3479,
3004, 2956, 2860, 1789, 1733, 1637, 1476, 1286, 1202, 1001, 912,
799.
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2,2-Dimethyl-5-(9Z,12Z)-(octadeca-9,12-dienylidene)-1,3-dioxane-
4,6-dione (9i). Yield 76%. Yellow liquid. H NMR (300 MHz, CDCl3):
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2,2-Dimethyl-5-(octylidene)-1,3-dioxane-4,6-dione (9c). Yield 92%.
Yellow liquid. 1H NMR (300 MHz, CDCl3): 0.90 (t, 3H, J = 6.0 Hz), 1.30
(m, 10H), 1.61 (quint, 2H, J = 6.0 Hz), 1.76 (s, 6H), 2.96 (q, 2H, J = 6.0
Hz), 7.95 (t, 1H, J = 6.0 Hz). 13C NMR (75 MHz, CDCl3): 14.7, 23.2,
28.3, 28.8, 29.6, 30.0, 31.8, 32.3, 105.4, 118.7, 160.5, 162.5, 165.6,
169.7. IR max, cm-1): 3446, 3009, 2936, 2855, 1795, 1746, 1624,
1560, 1357, 1301, 1195, 1017, 928, 799.
0.90 (t, 3H, J = 6.0 Hz), 1.32 (m, 14H), 1.76 (s, 6H), 2.06 (m, 4H), 2.79
(m, 2H), 2.95 (m, 2H), 5.36 (m, 4H), 7.94 (t, 1H, J = 6.0 Hz). 13C NMR
(75 MHz, CDCl3): 14.1, 22.7, 25.6, 26.3, 27.2 (2C), 27.9 (2C), 29.7
(2C), 29.8(2C), 29.9(2C), 31.9, 104.6, 125.7, 127.3, 127.7, 130.0,
130.3, 155.7, 162.4, 165.0. IR max, cm-1): 3478, 3017, 2936, 2839,
1730, 1629, 1454, 1381, 1284, 1195, 1025, 912, 710.
Synthesis of Michael adducts 10a-i.
2,2-Dimethyl-5-(decylidene)-1,3-dioxane-4,6-dione (9d). Yield 85%.
Pale yellow paste. 1H NMR (300 MHz, CDCl3): 0.88 (t, 3H, J = 6.0 Hz),
1.26 (m, 10H), 1.59 (m, 2H), 1.74 (s, 6H), 2.94 (q, 2H, J = 9.0 Hz), 7.93
(t, 1H, J = 7.5 Hz). 13C NMR (75 MHz, CDCl3): 14.7, 23.3, 28.3 (2C),
28.8, 28.9, 29.9, 30.0, 30.1, 31.8, 32.5, 105.5, 118.7, 160.5, 162.6,
169.7. IR max, cm-1): 3009, 2928, 2847, 1792, 1752, 1738, 1639,
1467, 1381, 1296, 1201, 1002, 925, 799.
To a round-bottom flask equipped with a magnetic stirring bar, the
long-chain alkylidene (9a-i, 1 mmol) was added. In the next step,
CH3NO2 (5 mmol) and DBU (1 mmol) were added. The mixture was
kept under stirring at room temperature for 8 hours. Afterwards, the
excess of nitromethane was evaporated under reduced pressure and
the crude was dissolved in 20 mL of CH2Cl2 and washed with 1% HCl
(3 x 10 mL). The organic solution was dried over MgSO4 and solvent
evaporated under reduced pressure, giving long-chain nitro adducts
10a-i.
2,2-Dimethyl-5-(dodecylidene)-1,3-dioxane-4,6-dione (9e). Yield
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86%. Pale yellow solid. Melting point 67-69 °C. H NMR (300 MHz,
CDCl3): 0.91 (t, 3H, J = 7.5 Hz), 1.28 (m, 16H), 1.62 (m, 2H), 1.76 (s,
6H), 2.96 (q, 2H, J = 6.0 Hz), 7.96 (dt, 1H, J = 9.0 e 6.0 Hz). 13C NMR
(75 MHz, CDCl3): 14.7, 23.3, 28.3, 28.8, 29.9(2C), 30.1(2C), 30.2(2C),
31.6, 31.8, 32.5, 105.4, 118.7, 160.5, 162.6, 169.7. IR max, cm-1):
3398, 3009, 2920, 2847, 1802, 1748, 1738, 1641, 1568, 1462, 1381,
1309, 1203, 1009, 912, 807, 718.
2,2-dimethyl-5-(4-methyl-1-nitropentan-2-yl)-1,3-dioxane-4,6-
dione (10a).32 Yield 95%. Pale yellow solid. Melting point 73-75 °C. 1H
NMR (300 MHz, CDCl3): 0.94 (d, 3H, J = 6.0 Hz), 0.98 (d, 3H, J = 6.0
Hz), 1.20 (m, 1H), 1.55 (m, 2H), 1.79 (s, 3H), 1.81 (s, 3H), 3.36 (m, 1H),
3.89 (d, 1H, J = 3.0 Hz), 4.53 (dd, 1H, J = 12.0 e 6.0 Hz), 4.98 (dd, 1H,
J = 12.0 e 9.0 Hz). 13C NMR (75 MHz, CDCl3): 21.4, 23.1, 25.6, 26.8,
28.2, 34.3, 38.1, 47.1, 75.7, 105.4, 163.9, 164.1. IR max, cm-1): 2958,
2873, 1782, 1754, 1549, 1549, 1307, 1195, 980, 631.
2,2-Dimethyl-5-(hexadecylidene)-1,3-dioxane-4,6-dione (9f). Yield
80%. White solid. Melting point 81-83 °C. 1H NMR (300 MHz, CDCl3):
0.88 (t, 3H, J = 6.0 Hz), 1.28 (m, 24H), 1.60 (m, 2H), 1.74 (s, 6H), 2.94
(q, 2H, J = 6.0 Hz), 7.93 (t, 1H, J = 7.5 Hz). 13C NMR (75 MHz, CDCl3):
14.0, 27.6(2C), 28.1, 29.2, 29.3(2C), 29.4(2C), 29.5(2C), 29.6(4C),
31.1, 31.9, 104.7, 118.0, 159.8, 161.9, 169.0. IR max, cm-1): 3001,
2920, 2855, 1795, 1746, 1730, 1641, 1462, 1381, 1301, 1195, 1001,
799, 718.
2,2-Dimethyl-5-(1-nitroheptan-2-yl)-1,3-dioxane-4,6-dione (10b).
Yield 95%. Yellow viscous liquid. 1H NMR (300 MHz, CDCl3): 0.87 (t,
3H, J = 7.5 Hz), 1.28-1.58 (m, 8H), 1.77 (s, 3H), 1.79 (s, 3H), 3.25 (m,
1H), 3.89 (d, 1H, J = 3 Hz), 4.55 (dd, 1H, J = 12.0 e 6.0 Hz), 4.93 (dd,
1H, J = 15.0 e 9.0 Hz). 13C NMR (75 MHz, CDCl3): 14.1, 22.8, 23.9,
25.7, 26.8, 26.9, 29.6, 33.2, 49.0, 76.2, 105.4, 164.1, 164.9. IR max
,
cm-1): 2906, 2863, 1778, 1730, 1560, 1397, 1317, 1203, 1047, 841,
685.
2,2-dimethyl-5-(octadecylidene)-1,3-dioxane-4,6-dione (9g). Yield
83%. White solid. Melting point 78-79 °C. 1H NMR (300 MHz, CDCl3):
0.90 (t, 3H, J = 7.5 Hz), 1.27 (m, 28H), 1.61 (m, 2H), 1.76 (s, 6H), 2.95
(q, 2H, J = 6.0 Hz), 7.95 (t, 1H, J = 7.5 Hz). 13C NMR (75 MHz, CDCl3):
13.6, 22.4, 27.2(2C), 27.7, 28.8(2C), 28.9(2C), 29.0(2C), 29.1(2C),
29.2(4C), 30.7, 31.4, 104.3, 117.5, 159.3, 161.4, 168.5. IR max, cm-1):
3001, 2920, 2847, 1786, 1738, 1624, 1471, 1390, 1293, 1195, 1009,
799, 718.
2,2-Dimethyl-5-(1-nitrononan-2-yl)-1,3-dioxane-4,6-dione
(10c).
Yield 90%. Yellow viscous liquid. 1H NMR (300 MHz, CDCl3): 0.90 (t,
3H, J = 7.5 Hz), 1.28-1.42 (m, 12H), 1.81 (s, 3H), 1.83 (s, 3H), 3.30 (m,
1H), 3.92 (m, 1H), 4.58 (dd, 1H, J = 15.0 e 6.0 Hz), 5,00 (dd, 1H, J =
12.0 e 9.0 Hz). 13C NMR (75 MHz, CDCl3): 14.1, 22.8, 23.7, 25.9, 26.9,
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J. Name., 2013, 00, 1-3 | 3
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