The Journal of Organic Chemistry
Article
(m, 3H), δ 0.93 (m, 3H), 1.09 (m, 21H), 1.09 (m, 21H), 1.30 (s, 9H),
1.30 (s, 9H), 1.50 (m, 2H), 1.50 (m, 2H), 2.21 (t, J = 7.6 Hz, 2H),
2.55 (m, 2H), 2.55 (m, 4H), 2.66 (m, 2H), 2.66 (m, 2H), 5.61 (s, 1H),
5.65 (s, 1H); 13C NMR (100 MHz, CDCl3) δ 12.7, 12.9, 14.1, 18.10,
18.11, 20.0, 21.0, 27.3, 29.6, 29.9, 33.6, 39.2, 39.4, 39.7, 40.3, 102.7,
103.2, 121.0, 122.0, 147.9, 153.0, 153.69, 153.74, 175.7, 176.6, 197.3,
199.3; IR (film) ν 2962, 2868, 1744, 1701, 1638, 1598, 1462, 1375,
1253, 1107, 998, 881, 684, 666 cm−1; HRMS (ESI) m/z calcd. for
C24H42O4Si (M + Na)+ 445.2744, found 445.2734.
2,2-Dimethyl-1-(6-oxocyclohex-2-en-1-ylidene)propyl Piva-
late (4b, A Mixture E and Z Isomers). Yield 70 mg, 72%; colorless
oil: 1H NMR (500 MHz, CDCl3, TMS) δ 1.17 (s, 9H), δ 1.21 (s, 9H),
1.23 (s, 9H), 1.33 (s, 9H), 2.38 (m, 4H), 2.60 (m, 4H), 5.74 (m, 1H),
5.79 (dt, J = 10.0, 4.0 Hz, 1H), 5.84 (m, 1H), 6.10 (dt, J = 10.0, 1.5
Hz, 1H); 13C NMR (125 MHz, CDCl3) δ 23.3, 25.4, 26.9, 27.1, 27.5,
28.4, 28.8, 37.9, 39.0, 39.5, 41.5, 44.7, 122.5, 124.0, 125.1, 125.2, 125.3,
128.5, 145.8, 159.0, 175.9, 176.1, 202.4, 210.4; IR (film) ν 2970, 1746,
1694, 1478, 1122, 1096, 731, 707 cm−1; HRMS (ESI) m/z calcd. for
C16H24O3 (M + Na)+ 287.1617, found 287.1610.
2H), 5.78 (tq, J = 4.8, 1.6 Hz, 1H); 13C NMR (100 MHz, CDCl3) δ
22.4, 23.7, 27.3, 27.4, 32.9, 38.6, 38.8, 39.4, 62.1, 128.9, 130.0, 132.2,
151.7, 176.0, 178.5, 202.6; IR (film) ν 2971, 1727, 1698, 1281, 1147,
1097, 1031 cm−1; HRMS (ESI) m/z calcd. For C20H30O5 (M + Na)+
373.1985, found 373.1979.
(Z)-1-(2-Methyl-6-oxocyclohex-2-en-1-ylidene)propane-1,3-
diyl Bis(2,2-dimethylpropanoate) (Z-4f). Yield 41.0 mg, 84%
1
combined yield; colorless oil: H NMR (500 MHz, CDCl3, TMS) δ
1.17 (s, 9H), δ 1.25 (s, 9H), 1.72 (q, J = 1.5 Hz, 3H), 2.31 (m, 4H),
2.89 (t, J = 6.5 Hz, 2H), 4.34 (t, J = 6.5 Hz, 2H), 5.52 (m, 1H); 13C
NMR (125 MHz, CDCl3) δ 19.6, 23.1, 26.4, 27.2, 27.4, 38.9, 39.2,
43.3, 59.5, 121.6, 127.9, 129.1, 149.5, 176.1, 178.5, 201.4; IR (film) ν
2973, 1726, 1480, 1363, 1282, 1151, 1106, 133, 909, 729 cm−1; HRMS
(ESI) m/z calcd. for C20H30O5 (M + Na)+ 373.1985, found 373.1979.
(E)-1-(2,3-Dimethyl-6-oxocyclohex-2-en-1-ylidene)butyl Piv-
1
alate (E-4g). Yield 30.3 mg, 52%; colorless oil: H NMR (400 MHz,
CDCl3, TMS) δ 0.93 (t, J = 7.6 Hz, 3H), δ 1.28 (s, 9H), 1.52 (sextet, J
= 7.6 Hz, 2H), 1.78 (s, 3H), 1.79 (s, 3H), 2.31 (m, 2H), 2.39 (m, 2H),
2.55 (t, J = 7.6 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ 13.9, 17.8,
19.9, 21.3, 27.4, 29.4, 33.9, 37.6, 39.3, 124.5, 129.5, 134.7, 154.2, 175.5,
204.0; IR (film) ν 2963, 1744, 1696, 1608, 1479, 1461, 1273, 1101,
1027, 914, 731 cm−1; HRMS (ESI) m/z calcd. for C17H26O3 (M +
Na)+ 301.1774, found 301.1771.
(E)-1-(2-Methyl-6-oxocyclohex-2-en-1-ylidene)-4-phenylbu-
1
tyl Pivalate (E-4c). Yield 37.3 mg, 55%; colorless oil: H NMR (500
MHz, CDCl3, TMS) δ 1.23 (s, 9H), δ 1.86 (m, 2H), 1.89 (q, J = 1.5
Hz, 3H), 2.38(m, 2H), 2.49 (t, J = 7.5 Hz, 2H), 2.57 (t, J = 7.5 Hz,
2H), 2.65 (t, J = 8.0 Hz, 2H), 5.73 (tq, J = 4.5, 1.5 Hz, 1H), 7.16 (m,
3H), 7.26 (m, 2H); 13C NMR (125 MHz, CDCl3) δ 22.5, 23.9, 27.3,
29.9, 32.8, 35.8, 38.9, 39.4, 126.0, 127.5, 128.2, 128.5, 128.6, 132.5,
142.2, 155.9, 175.9, 203.1; IR (film) ν 2972, 1744, 1696, 1603, 1454,
1269, 1104, 910, 731, 699 cm−1; HRMS (ESI) m/z calcd. for
C22H28O3 (M + Na)+ 363.1931, found 363.1938.
(Z)-1-(2-Methyl-6-oxocyclohex-2-en-1-ylidene)-4-phenylbu-
tyl Pivalate (Z-4c). Yield 21.3 mg, 31%; colorless oil: 1H NMR (400
MHz, CDCl3, TMS) δ 1.18 (s, 9H), δ 1.67 (d, J = 1.2 Hz, 3H), 1.92
(pentet, J = 7.6 Hz, 2H), 2.29(m, 4H), 2.55 (t, J = 7.6 Hz, 2H), 2.63
(t, J = 7.6 Hz, 2H), 5.49 (m, 1H), 7.17 (m, 3H), 7.27 (m, 2H); 13C
NMR (100 MHz, CDCl3) δ 19.5, 23.1, 25.4, 26.1, 27.1, 35.4, 39.1,
43.9, 121.3, 126.2, 128.4, 128.59, 128.63, 129.0, 141.7, 148.0, 176.2,
205.0; IR (film) ν 2935, 1748, 1697, 1453, 1364, 1276, 1252, 1229,
1107, 909, 730, 699 cm−1; HRMS (ESI) m/z calcd. for C22H28O3 (M
+ Na)+ 363.1931, found 363.1945.
1-(2-Methyl-6-oxocyclohex-2-en-1-ylidene)-4-phenylbutyl
Acetate (4d, A Mixture E and Z Isomers). Yield 36.3 mg, 84%;
colorless oil: 1H NMR (400 MHz, CDCl3, TMS) δ 1.68 (q, J = 1.2 Hz,
3H), δ 1.84 (m, 2H), 1.92 (s, 3H), 1.94(m, 2H), 2.03 (s, 3H), 2.15 (s,
3H), 2.27 (m, 2H), 2.36 (m, 4H), 2.48(m, 2H), 2.56 (t, J = 7.2 Hz,
2H), 2.64 (m, 6H), 5.50 (m, 1H), 5.76 (tq, J = 4.8, 1.2 Hz, 1H),
7.18(m, 3H), 7.18(m, 3H), 7.27 (m, 2H), 7.27 (m, 2H); 13C NMR
(100 MHz, CDCl3) δ 19.6, 20.9, 21.4, 22.1, 23.1, 23.7, 25.4, 26.3, 29.5,
32.7, 35.3, 35.7, 38.7, 43.7, 121.5, 126.0, 126.2, 127.2, 128.49, 128.57,
128.58, 128.65, 128.8, 129.0, 132.2, 141.7, 142.2, 148.3, 155.5, 168.1,
168.4, 202.9, 204.7; IR (film) ν 2941, 1762, 1695, 1602, 1453, 1367,
1208, 1187, 1037, 1013, 700 cm−1; HRMS (ESI) m/z calcd. for
C19H22O3 (M + Na)+ 321.1461, found 321.1482.
1-(2-Methyl-6-oxocyclohex-2-en-1-ylidene)-3-
((triisopropylsilyl)oxy)propyl Pivalate (4e, A Mixture E and Z
Isomers). Yield 39 mg, 91%; colorless oil: 1H NMR (500 MHz,
CDCl3, TMS) δ 1.10 (m, 21H), δ 1.10 (m, 21H), 1.29 (s, 9H), 1.33 (s,
9H), 1.77(s, 3H), 1.95 (q, J = 1.5 Hz, 3H), 2.33 (m, 4H), 2.42 (m,
2H), 2.53 (m, 2H), 2.84(m, 4H), 3.91 (t, J = 7.0 Hz, 2H), 4.03 (t, J =
6.5 Hz, 2H), 5.54 (m, 1H), 5.78 (m, 1H); 13C NMR (125 MHz,
CDCl3) δ 12.1, 12.2, 18.16, 18.19, 19.6, 22.5, 23.1, 23.8, 26.3, 27.2,
27.3, 37.4, 38.7, 39.2, 39.4, 47.9, 59.0, 62.1, 121.2, 128.3, 128.5, 129.5,
132.4, 148.7, 153.4, 176.0, 176.1, 202.8, 203.4; IR (film) ν 2942, 2866,
1747, 1698, 1462, 1382, 1271, 1096, 1027, 935, 881, 680 cm−1; HRMS
(ESI) m/z calcd. for C24H42O4Si (M + Na)+ 445.2744, found
445.2735.
(S)-1-(4-Methyl-4-(4-methylpent-3-en-1-yl)-6-oxocyclohex-
2-en-1-ylidene)-4-phenylbutyl Pivalate (4h, A Mixture E and Z
Isomers). Yield 67 mg, 62%; colorless oil: 1H NMR (500 MHz,
CDCl3, TMS) δ 1.06 (s, 3H), 1.28 (s, 9H), 1.37 (m, 2H), 1.57 (s, 3H),
1.65 (s, 3H), 1.83 (m, 2H), 1.93 (m, 2H), 2.37 (m, 1H), 2.37 (d, J =
14.0 Hz, 1H), 2.56 (d, J = 14.0, 1H), 2.65 (t, J = 8.0 Hz, 2H), 2.80
(ddd, J = 8.0, 7.5, 1.5 Hz, 1H), 5.05 (m, 1H), 5.72 (d, J = 10.0 Hz,
1H), 6.21 (d, J = 10.0 Hz, 1H), 7.16−7.30 (m, 5H); the two isomers
1
have nearly identical H NMR; 13C NMR (125 MHz, CDCl3) δ 17.8,
23.3, 25.84, 25.85, 27.27, 27.34, 29.2, 31.8, 35.4, 35.8, 39.3, 39.5, 39.9,
42.4, 53.3, 120.8, 122.3, 124.2, 126.0, 126.2, 128.5, 128.58, 128.60,
132.0, 138.2, 142.2, 157.5, 175.7, 176.0, 200.0; IR (film) ν 2967, 1712,
1454, 1361, 1220, 1123, 914, 732, 700 cm−1; HRMS (ESI) m/z calcd.
for C28H38O3 (M + Na)+ 445.2613, found 445.2607.
1-Cyclopropyl-3-phenylpropa-1,2-dienyl Pivalate (8d). Yield
49 mg, 49%; colorless oil: 1H NMR (400 MHz, CDCl3, TMS) δ 0.62−
0.64 (m, 2H), 0.75−0.78 (m, 2H), 1.26 (s, 9H), 1.54−1.60 (m, 1H),
6.59 (d, J = 2.0 Hz, 1H), 7.24−7.26 (m, 1H), 7.31−7.35 (m, 2H),
7.41−7.43 (m, 2H); 13C NMR (100 MHz, CDCl3) δ 5.8, 6.3, 12.3,
27.4, 39.4, 105.0, 128.1, 128.2, 128.5, 128.9, 134.2, 176.2, 196.8;
HRMS (ESI) m/z calcd. for C17H20O2 (M + Na)+ 279.1356, found
279.1360.
General Procedures for the Synthesis of Compound 13 and
14. To an oven-dried flask were added [Rh(CO)2Cl]2 (2 mol %),
anhydrous toluene (0.1 M), and 1 equiv of cyclopropyl propargyl
ester. The oil bath was heated to 60 °C. The reaction was monitored
by TLC. After the reaction was complete, the solvent was evaporated,
and the residue was purified by flash column chromatography on silica
gel (EtOAc/hexane = 50:1).
2-(Propan-2-ylidene)-2,4,5,6,7,7a-hexahydro-1H-inden-3-yl
1
Pivalate (13). Yield 35 mg, 89%; colorless oil: H NMR (400 MHz,
CDCl3, TMS) δ 1.03−1.12 (m, 2H), 1.19−1.28 (m, 2H), 1.31 (s, 9H),
1.64 (s, 3H), 1.70−1.82 (m, 5H), 1.91−1.98 (m, 1H), 2.06 (d, br, J =
16.0 Hz, 1H), 219−2..23 (m, 1H), 2.42−2.50 (m, 1H), 2.73 (dd, J =
16.0, 8.0 Hz, 1H); 13C NMR (100 MHz, CDCl3) δ 19.3, 23.2, 25.3,
26.0, 26.2, 27.7, 35.2, 35.7, 39.3, 39.4, 119.2, 131.2, 138.0, 142.5, 176.3;
IR ν 2976, 2930, 2858, 2360, 2342, 1751, 1120; HRMS (ESI) m/z
calcd. for C17H26O2 (M + 1) 263.2006, found 263.2017.
1-(Propan-2-ylidene)-3a,4,5,7a-tetrahydro-1H-inden-2-yl
1
Pivalate (14). Yield 44 mg, 82%; colorless oil: H NMR (400 MHz,
CDCl3, TMS) δ 1.27 (s, 9H), 1.62−1.71 (m, 2H), 1.79 (s, 3H), 1.84
(s, 3H), 1.87−1.91 (m, 1H), 2.04−2.13 (m, 1H), 3.14 (s, br, 1H), 3.44
(s, br, 1H), 5.51−5.52 (m, 1H), 5.54 (s, 1H), 5.70−5.81 (m, 1H); 13C
NMR (100 MHz, CDCl3) δ 20.2, 21.1, 23.0, 24.8, 27.4, 37.8, 39.4,
41.3, 123.4, 124.1, 127.6, 127.7, 134.8, 151.4, 176.4; IR ν 2977, 2362,
2343, 1712, 1362, 1222; HRMS (ESI) m/z calcd. for C17H24O2 (M +
1) 261.1849, found 261.1840.
(E)-1-(2-Methyl-6-oxocyclohex-2-en-1-ylidene)propane-1,3-
diyl Bis(2,2-dimethylpropanoate) (E-4f). Yield 41.0 mg, 84%
1
combined yield; colorless oil: H NMR (400 MHz, CDCl3, TMS) δ
1.10 (s, 9H), δ 1.29 (s, 9H), 1.91 (q, J = 1.6 Hz, 3H), 2.40 (m, 2H),
2.51 (t, J = 6.8 Hz, 2H), 2.89 (t, J = 6.8 Hz, 2H), 4.22 (t, J = 7.2 Hz,
H
dx.doi.org/10.1021/jo300973r | J. Org. Chem. XXXX, XXX, XXX−XXX