The Journal of Organic Chemistry
Note
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[α]D −18.1 (c 1.0, CHCl3); H NMR (400 MHz, CDCl3, TMS,
ppm) δ 6.21−6.20 (m, 2H), 4.27−4.21 (m, 2H), 4.16−4.09 (m, 2H),
4.03 (q, J = 6 Hz, 1H), 3.81 (t, J = 12 Hz, 1H), 2.92 (q, J = 3.2 Hz,
1H), 2.67−2.59 (m, 2H), 2.12 (s, 3H), 1.96 (d, J = 12 Hz, 1H), 1.78−
1.72 (m, 2H), 1.64 (d, J = 10.4 Hz, 1H), 1.53 (d, J = 12.4 Hz, 1H),
1.49−1.45 (m, 1H), 1.31 (t, J = 7.2 Hz, 3H), 1.22−1.02 (m, 5H); 13C
NMR (100 MHz, CDCl3, TMS, ppm) δ 206.9, 168.0, 161.2, 140.5,
113.6, 93.9, 66.9, 66.2, 61.4, 52.0, 44.8, 40.0, 37.3, 34.0, 30.3, 26.6,
26.4, 25.9, 20.8, 14.1; HRMS (ESI) [C20H28O7 + Na]+, calc 403.1727,
found 403.1721. The dr and ee values were determined by HPLC with
Chiralpack AS−H column at 254 nm (hexane/i-PrOH = 80:20, flow
rate = 1.0 mL/min), for major diastereomer: tR = 10.5 min (major), tR
= 11.7 min (minor).
4.25 (q, J = 7.2 Hz, 2H), 2.47 (d, J = 18.0 Hz, 1H), 2.34 (t, J = 8.0 Hz,
2H), 2.10 (s, 3H), 2.06 (s, 3H), 2.00 (d, J = 18.0 Hz, 1H), 1.75−1.69
(m, 1H), 1.93−1.86 (m, 1H), 1.32 (t, J = 7.2 Hz, 3H); 13C NMR (100
MHz, CDCl3, TMS, ppm) δ 217.6, 168.6, 162.4, 136.5, 121.4, 91.5,
61.0, 49.7, 38.5, 37.9, 29.7, 20.9, 18.9, 18.5, 14.2; HRMS (EI)
[C15H20O6]+, calc 296.1260, found 296.1257. The dr and ee values
were determined by HPLC with Chiralpack AS−H column at 254 nm
(hexane/i-PrOH = 90:10, flow rate = 0.8 mL/min), for major
diastereomer: tR = 16.6 min (major), tR = 18.9 min (minor).
(5S,6R)-Ethyl 6-Acetoxy-1-oxo-7-oxaspiro[4.5]dec-8-ene-8-
carboxylate (5j). The title compound was obtained according to
the general procedure described above after flash column chromatog-
raphy (eluting with hexane/ethyl acetate 90/10) as a white solid (70
20
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mg, 83% yield, > 99:1 dr, 62% ee): [α]D −37.1 (c 1.0, CHCl3); H
NMR (500 MHz, CDCl3, TMS, ppm) δ 6.16 (q, J = 2.0 Hz, 1H), 6.07
(s, 1H), 4.26 (m, 2H), 2.50 (dd, J1 = 19 Hz, J2 = 3.0 Hz, 1H), 2.34 (m,
3H), 2.12 (m, 1H), 2.10 (s, 3H), 2.09 (m, 1H), 1.90 (m, 1H), 1.74 (m,
1H), 1.33 (t, J = 7.0 Hz, 3H); 13C NMR (125 MHz, CDCl3, TMS,
ppm) δ 217.9, 168.6, 161.6, 142.6, 110.0, 92.4, 61.7, 49.0, 38.8, 30.3,
29.6, 21.1, 19.2, 14.4; HRMS (EI) [C14H18O6]+, calc 282.1103, found
282.1101. The dr and ee values were determined by HPLC with
Chiralpack AS−H column at 254 nm (hexane/i-PrOH = 90:10, flow
rate = 0.8 mL/min), for major diastereomer: tR = 28.7 min (major), tR
= 34.4 min (minor).
(1R,5R,6R)-Diethyl 1-Acetoxy-5-heptyl-11-oxo-2-oxa-8-
azaspiro[5.5]undec-3-ene-3,8-dicarboxylate (5f). The title com-
pound was obtained according to the general procedure described
above after flash column chromatography (eluting with hexane/ethyl
acetate 80/20) as a white solid (101 mg, 72% yield, 99:1 dr, >99% ee):
[α]D −27.6 (c 1.04, CHCl3); H NMR (400 MHz, CDCl3, TMS,
ppm) δ 6.23 (d, J = 28 Hz, 1H), 6.18 (s, 1H), 4.24−4.11 (m, 5H), 4.02
(t, J = 5.6 Hz, 1H), 3.57 (s, 1H), 3.49 (d, J = 14.4 Hz, 1H), 2.97−2.74
(m, 2H), 2.53−2.44 (m, 1H), 2.12 (s, 3H), 1.51 (s, 2H), 1.35−1.25
(m, 18H), 0.89−0.83 (m, 4H); 13C NMR (100 MHz, CDCl3, TMS,
ppm) δ 171.9, 171.5, 169.2, 168.8, 162.8, 133.6, 122.7, 121.4, 90.9,
90.7, 61.3, 60.9, 60.8, 48.5, 46.8, 32.4, 30.5, 28.1, 26.1, 21.0, 20.9, 19.1,
18.9, 14.2, 14.1, 14.0, 8.1, 8.1; HRMS (EI) [C24H37NO8]+, calc
467.2519, found 467.2517. 1721. The dr and ee values were
determined by HPLC with Chiralpack AS−H column at 254 nm
(hexane/i-PrOH = 85:15, flow rate = 0.8 mL/min), for major
diastereomer: tR = 5.6 min (major), tR = 8.4 min (minor).
(9S,10R,14R)-Methyl 10-Acetoxy-14-cyclopropyl-8-oxo-
1,4,11-trioxadispiro[4.3.5.1]pentadec-12-ene-12-carboxylate
(5g). The title compound was obtained according to the general
procedure described above after flash column chromatography (eluting
with hexane/ethyl acetate 70/30) as a white solid (105 mg, 89% yield,
99:1 dr, >99% ee): [α]D20 −25.6 (c 1.0, CHCl3); 1H NMR (400 MHz,
CDCl3, TMS, ppm) δ 6.81 (s, 1H), 6.23 (d, J = 3.2 Hz, 1H), 4.21 (q, J
= 7.2 Hz, 2H), 4.05−3.96 (m, 4H), 2.95−2.88 (m, 1H), 2.56−2.50 (m,
1H), 2.42 (dd, J1 = 2.8 Hz, J2 = 15.2 Hz, 1H), 2.11 (s, 3H), 2.08−2.00
(m, 2H), 1.90 (dd, J1 = 3.6 Hz, J2 = 10.4 Hz, 1H), 1.30 (t, J = 7.2
Hz,3H), 1.01 (m, 1H), 0.88 (t, J = 6.4 Hz, 1H), 0.61−0.54 (m, 2H),
0.24−0.16 (m, 2H); 13C NMR (100 MHz, CDCl3, TMS, ppm) δ
208.7, 168.1, 161.6, 138.6, 116.2, 106.9, 92.3, 64.7, 64.4, 61.2, 52.1,
36.8, 33.9, 31.5, 22.5, 20.7, 14.1, 14.0, 10.8, 7.1, 3.0; HRMS (EI)
[C20H26O8]+, calc 394.1628, found 394.1610. The dr and ee values
were determined by HPLC with Chiralpack AS−H column at 254 nm
(hexane/i-PrOH = 90:10, flow rate = 1.0 mL/min), for major
diastereomer: tR = 19.3 min (minor), tR = 30.0 min (major).
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(1R,5S,6S)-Methyl 1-Acetoxy-7-oxo-5-phenyl-2-
oxaspiro[5.5]undec-3-ene-3-carboxylate (7a). The title com-
pound was obtained according to the general procedure described
above after flash column chromatography (eluting with hexane/ethyl
acetate 85/15) as a white solid (87 mg, 81% yield, 99:1 dr, 96% ee):
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[α]D −60.1 (c 0.51, CHCl3); H NMR (400 MHz, CDCl3, TMS,
ppm) δ 7.30−7.19 (m, 5H), 6.70 (s, 1H), 6.37 (d, J = 7.6 Hz, 1H),
4.28 (d, J = 3.6 Hz, 1H), 3.81 (s, 3H), 2.66−2.58 (m, 1H), 2.30−2.23
(m, 1H), 2.05 (s, 3H), 1.91−1.87 (m, 1H), 1.65 (s, 3H), 1.61−1.54
(m, 1H), 1.30−1.10 (m, 2H); 13C NMR (100 MHz, CDCl3, TMS,
ppm) δ 210.5, 168.3, 161.9, 140.9, 137.6, 130.1, 128.0, 127.5, 115.7,
92.8, 52.9, 52.3, 44.0, 40.6, 31.5, 28.8, 25.3, 22.6, 20.8, 20.7, 14.0;
HRMS (ESI) [C20H22O6 + Na]+, calc 381.1309, found 381.1298. The
dr and ee values were determined by HPLC with Chiralpack AS−H
column at 254 nm (hexane/i-PrOH = 90:10, flow rate = 1.0 mL/min),
for major diastereomer: tR = 18.8 min (minor), tR = 31.0 min (major).
(5S,6R,10S)-Methyl 6-Acetoxy-10-(4-methoxyphenyl)-1-oxo-
7-oxaspiro[4.5]dec-8-ene-8-carboxylate (7b). The title com-
pound was obtained according to the general procedure described
above after flash column chromatography (eluting with hexane/ethyl
acetate 85/15) as a white solid (93 mg, 83% yield, 99:1 dr, 94% ee):
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[α]D −70.2 (c 1.0, CHCl3); H NMR (400 MHz, CDCl3, TMS,
ppm) δ 7.00 (d, J = 8.8 Hz, 2H), 6.81 (d, J = 8.8 Hz, 2H), 6.26 (d, J =
2.0 Hz, 1H), 6.14 (s, 1H), 4.23 (d, J = 2.0 Hz, 1H), 3.83 (s, 3H), 3.79
(s, 3H), 2.23−2.12 (m, 2H), 2.10 (s, 3H), 1.92−1.85 (m, 1H), 1.82−
1.69 (m, 2H), 0.74−0.67 (m, 1H); 13C NMR (100 MHz, CDCl3,
TMS, ppm) δ 219.6, 168.0, 161.6, 159.1, 142.8, 129.5, 129.2, 114.9,
114.0, 94.5, 55.2, 52.9, 52.4, 45.2, 39.5, 23.8, 20.7, 18.8; HRMS (EI)
[C20H22O7]+, calc 374.1366, found 374.1366. The dr and ee values
were determined by HPLC with Chiralcel OD−H column at 254 nm
(hexane/i-PrOH = 85:15, flow rate = 1.0 mL/min), for major
diastereomer: tR = 18.4 min (minor), tR = 34.3 min (major).
(5S,6R,10R)-Ethyl 6-Acetoxy-10-isopropyl-1-oxo-2,7-
dioxaspiro[4.5]dec-8-ene-8-carboxylate (5h). The title com-
pound was obtained according to the general procedure described
above after flash column chromatography (eluting with hexane/ethyl
acetate 70/30) as a white solid (64 mg, 65% yield, 94:6 dr, 96% ee):
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[α]D −52.9 (c 1.0, CHCl3); H NMR (500 MHz, CDCl3, TMS,
ppm) δ 6.15 (s, 1H), 6.01 (s, 1H), 4.47−4.40 (m, 2H), 4.30−4.25 (m,
2H), 2.73 (d, J = 10.0 Hz, 1H), 2.42 (m, 1H), 2.21−2.17 (m, 1H),
2.14 (s, 3H), 1.65−1.58 (m, 1H), 1.32 (t, J = 7.5 Hz, 3H), 1.11 (d, J =
6.5 Hz, 3H), 0.94 (d, J = 7.5 Hz, 3H); 13C NMR (125 MHz, CDCl3,
TMS, ppm) δ 178.1, 167.9, 161.3, 141.5, 113.5, 94.4, 66.8, 61.8, 47.5,
45.9, 28.7, 22.0, 21.3, 21.1, 21.0, 14.3; HRMS (EI) [C17H24O6]+, calc
324.1573, found 324.1569. The dr and ee values were determined by
HPLC with Chiralpack AS−H column at 254 nm (hexane/i-PrOH =
80:20, flow rate = 1.0 mL/min), for major diastereomer: tR = 11.0 min
(minor), tR = 21.8 min (major).
(5S,6R,10S)-Ethyl 6-Acetoxy-1-oxo-10-o-tolyl-7-oxaspiro-
[4.5]dec-8-ene-8-carboxylate (7c). The title compound was
obtained according to the general procedure described above after
flash column chromatography (eluting with hexane/ethyl acetate 85/
15) as a white solid (87 mg, 78% yield, 97:3 dr, 98% ee): [α]D20 −38.1
(c 0.49, CHCl3); 1H NMR (400 MHz, CDCl3, TMS, ppm) δ 7.18 (m,
4H), 6.22 (s, 1H), 6.16 (d, J = 2.0 Hz, 1H), 4.52 (d, J = 2.4 Hz, 1H),
4.29 (q, J = 7.2 Hz, 2H), 2.26 (m, 1H), 2.22 (s, 3H), 2.14(m, 1H),
2.09 (s, 3H), 1.90 (m, 1H), 1.73 (m, 1H), 1.33 (t, J = 7.2 Hz, 3H),
0.81 (m, 1H); 13C NMR (100 MHz, CDCl3, TMS, ppm) δ 219.6,
168.0, 161.2, 142.6, 136.2, 135.9, 131.1, 129.7, 127.6, 126.0, 116.5,
94.6, 61.4, 52.4, 39.0, 24.2, 20.7, 19.8, 19.0, 14.1; HRMS (ESI)
[C21H24O6 + Na]+, calc 395.1465, found 395.1456. The dr and ee
values were determined by HPLC with Chiralcel OD−H column at
(5S,6R)-Ethyl 6-Acetoxy-9-methyl-1-oxo-7-oxaspiro[4.5]dec-
8-ene-8-carboxylate (5i). The title compound was obtained
according to the general procedure described above after flash column
chromatography (eluting with hexane/ethyl acetate 90/10) as a white
20
solid (72 mg, 81% yield, > 99:1 dr, 70% ee): [α]D +55.7 (c 1.0,
1
CHCl3); H NMR (400 MHz, CDCl3, TMS, ppm) δ 5.99 (s, 1H),
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dx.doi.org/10.1021/jo202633c | J. Org. Chem. 2012, 77, 2959−2965