A. Guingant et al.
FULL PAPER
mixture was then filtered, concentrated and purified by silica gel
chromatography (EtOAc/petroleum ether 1:1) to afford the alde-
hyde 8b as a clear oil (2.01 g, 93% yield). [α]2D0 = –10.1 (c =
H, CH2–C=, 1-H, 2-H, 3a-H and 5a-H), 1.74 (sl, 1 H, OH), 1.36–
1.62 (m, 6 H, 3b-H, 5b-H and CH2-CH2-CH2O) ppm. 13C NMR
(75 MHz, CDCl3): δ = 159.2, 134.1, 130.7, 130.4, 129.3, 113.8, 95.3,
0.5, CHCl3). 1H NMR (300 MHz, CDCl3): δ = 9.68, (s, 1 H, CHO), 77.0, 65.5, 55.3, 46.0, 44.5, 40.6, 36.0, 32.3, 29.3, 26.1 ppm. IR
4.55 and 4.56 (AB system, J = 6.9 Hz, 2 H, CH2 MOM), 4.20–4.24
(m, 1 H, CH–O), 3.70 (s, 3 H, CO2CH3), 3.38–3.49 (m, 1 H, 2-H),
3.31 (s, 3 H, CH3 MOM), 3.03–3.11 (m, 1 H, 1-H), 2.09–2.22 (m,
3 H, 3a-H and 5-H), 1.91–2.01 (m, 1 H, 3b-H) ppm. 13C NMR
(75 MHz, CDCl3): δ = 201.5, 175.2, 94.9, 77.3, 55.6, 52.9, 52.3,
(film): ν = 3442, 2932, 2857, 1612, 1513, 1437, 1248, 1100, 1039,
˜
970, 917, 821, 758 cm–1. HRMS (ESI): calcd. for C22H34O6Na [M
+ Na]+ 401.2304; found 401.230.
(1R,2S,4S)-2-[(E)-6-(4-Methoxybenzyloxy)hex-1-enyl]-4-(methoxy-
methoxy)cyclopentanecarbaldehyde (44): The aldehyde 44 was pre-
pared by a procedure similar to that described above for 37, start-
ing from the alcohol 43 (400 mg, 1.06 mmol). Compound 44 was
isolated as a colourless oil (355 mg, 89% yield) after purification
of the crude product by silica gel chromatography (EtOAc/petro-
leum ether 1:3). [α]2D0 = –29.8 (c = 0.5, CHCl3). 1H NMR
(300 MHz, CDCl3): δ = 9.61 (s, 1 H, CH=O), 7.25 (d, J = 8.4 Hz,
2 H, Ar-H), 6.87 (d, J = 8.4 Hz, 2 H, Ar-H), 5.44 (m, 2 H,
CH=CH), 4.62 (s, 2 H, CH2 MOM), 4.42 (s, 2 H, OCH2–Ar), 4.14
(m, 1 H, CH–O), 3.79 (s, 3 H, ArOCH3), 3.41 (t, J = 6.3 Hz, 2 H,
CH2CH2O), 3.35 (s, 3 H, CH3 MOM), 2.59–2.79 (m, 2 H, 1-H and
2-H), 2.25 (m, 1 H, 3a-H), 1.86–2.13 (m, 4 H, 5-H and CH2C=),
1 . 5 9 ( m , 3 H , 3 b - H a n d C H 2 C H 2 C = ) , 1 . 3 9 ( m , 2 H ,
CH2CH2O) ppm. 13C NMR (75 MHz, CDCl3): δ = 202.9, 159.2,
132.1, 131.3, 130.8, 129.3, 113.9, 95.5, 76.8, 72.6, 70.0, 55.9, 55.4,
41.7, 36.6, 33.6 ppm. IR (film): ν = 2952, 2824, 2725, 1732, 1437,
˜
1210, 1149, 1098, 1035 cm–1. HRMS: because of the high propen-
sity of aldehyde 8b to oxidise, exact mass determination was not
possible.
Methyl (1R,2R,4S)-2-[(E)-2-Iodoethenyl]-4-(methoxymethoxy)cyclo-
pentanecarboxylate (7b): This compound was prepared by a pro-
cedure similar to that described above for 7a, from the starting
aldehyde 8b (300 mg, 1.4 mmol). Compound 7b was obtained as
an orange oil (423 mg, 89% yield) after purification of the crude
product by silica gel chromatography (EtOAc/petroleum ether 1:9).
1
The Z/E ratio (3:97) was determined by H NMR analysis (vinylic
protons). [α]2D0 = –42.4 (c = 0.5, CHCl3). 1H NMR (300 MHz,
CDCl3): δ = 6.52 (dd, J = 7.6, 14.4 Hz, 1 H, CH=CHI), 6.10 (d, J
= 14.4 Hz, 1 H, CH=CHI), 4.61 (s, 2 H, CH2 MOM), 4.17–4.26
(m, 1 H, CH–O), 3.68 (s, 3 H, CO2CH3), 3.35 (s, 3 H, CH3 MOM),
2.70–2.83 (m, 2 H, 1-H and 2-H), 2.21–2.33 (m, 1 H, 3a-H), 1.92–
2.14 (m, 2 H, 5-H), 1.51–1.65 (m, 1 H, 3b-H) ppm. 13C NMR
(75 MHz, CDCl3): δ = 175.1, 148.1, 95.6, 77.0, 75.7, 55.5, 52.0,
42.7, 40.2, 33.2, 32.2, 29.3, 26.0 ppm. IR (film): ν = 3442, 2952,
˜
2824, 2725, 1732, 1612, 1513, 1437, 1248, 1100, 1039, 970, 917,
821, 758 cm–1. HRMS (ESI): calcd. for C22H32O6Na [M + Na]+
399.2147; found 399.215.
48.2, 47.7, 38.8, 37.0 ppm. IR (film): ν = 3054, 2949, 1735, 1604,
˜
Methyl (2E,4R)-4-Hydroxy-4-{(1R,2S,4S)-2-[(E)-6-(4-methoxyben-
zyloxy)hex-1-enyl]-4-(methoxymethoxy)cyclopentyl}but-2-enoate
(45) and Methyl (2E,4S)-4-Hydroxy-4-{(1R,2S,4S)-2-[(E)-6-(4-
methoxybenzyloxy)hex-1-enyl]-4-(methoxymethoxy)cyclopentyl}but-
2-enoate (46): CrCl2 (1.6 g, 13 mmol) containing NiCl2 (0.1%,
2 mg, 0.013 mmol) was added to a solution of the aldehyde 44
(800 mg, 2.12 mmol) and methyl 3-iodoacrylate[40] (1.352 g,
6.37 mmol) in DMF (54 mL). The resultant dark green mixture
was stirred for 20 h at room temperature, quenched with saturated
NH4Cl and extracted with EtOAc. The combined extracts were
washed with brine and dried with MgSO4, and the solvents were
evaporated. The diastereomeric alcohols 45 (328 mg, 38% yield)
and 46 (321 mg, 34% yield) were separated by silica gel chromatog-
raphy (Et2O/petroleum ether 1:1) and isolated as colourless oils.
1437, 1206, 1098, 1041, 955, 917, 787 cm–1. HRMS (ESI): calcd.
for C11H17IO4Na [M + Na]+ 363.0067; found 363.007.
Methyl (1R,2S,4S)-2-{(E)-6-[(4-Methoxybenzyl)oxy]hex-1-en-1-yl}-
4-(methoxymethoxy)cyclopentanecarboxylate (6b): This compound
was prepared by a procedure similar to that described above for
6a, from the starting vinylic iodide 7b (150 mg, 0.441 mmol). The
coupling product 6b was isolated as a colourless oil (126 mg, 70%
yield) after purification of the crude product by silica gel
chromatography (EtOAc/petroleum ether 1:9). [α]2D0 = –32.5 (c =
0.5, CHCl3). 1H NMR (300 MHz, CDCl3): δ = 7.24 (d, J = 8.5 Hz,
2 H, Ar-H), 6.87 (d, J = 8.5 Hz, 2 H, Ar-H), 5.41 (m, 2 H,
CH=CH), 4.61 (s, 2 H, CH2 MOM), 4.41 (s, 2 H, OCH2–Ar), 4.19
(m, 1 H, CH–O), 3.79 (s, 3 H, ArOCH3), 3.63 (s, 3 H, CO2CH3),
3.41 (t, J = 6.5 Hz, 2 H, CH2CH2O), 3.34 (s, 3 H, CH3 MOM),
2.65 (m, 2 H, 1-H and 2-H), 2.26 (m, 1 H, 3a-H), 1.95–2.06 (m, 4
H, 5-H and CH2C=), 1.45–1.67 (m, 3 H, 3b-H and CH2–CH2C=),
1.36–1.44 (m, 2 H, CH2–CH2O) ppm. 13C NMR (75 MHz, CDCl3):
δ = 175.8, 159.2, 132.3, 130.9, 130.8, 129.3, 113.8, 95.4, 77.2, 72.6,
70.0, 55.4, 55.3, 51.7, 48.7, 45.8, 37.1, 32.2, 29.2, 26.0, 22.1 ppm.
Data for 45: [α]2D0 = –4.8 (c = 0.5, CHCl3). 1H NMR (300 MHz,
CDCl3): δ = 7.25 (d, J = 8.4 Hz, 2 H, Ar-H), 6.96 (dd, J = 4.2,
15.6 Hz, 1 H, =CH–CHOH), 6.87 (d, J = 8.4 Hz, 2 H, Ar-H), 6.01
(d, J = 15.6 Hz, 1 H, =CH–CO2Me), 5.27–5.46 (m, 2 H, CH=CH),
4.59 (s, 2 H, CH2 MOM), 4.42 (s, 2 H, OCH2–Ar), 4.34 (m, 1 H,
CH–OH), 4.10 (m, 1 H, CH–OMOM), 3.80 (s, 3 H, ArOCH3), 3.73
(s, 3 H, CO2CH3), 3.43 (t, J = 6.3 Hz, 2 H, CH2CH2O), 3.33 (s, 3
H, CH3 MOM), 2.37 (m, 1 H, CH–CH=), 2.21 (m, 1 H, 1 H of
CH2–CHCH=), 1.91–2.06 (m, 3 H, CHCHOH and CH2–CH=),
1.31–1.82 (m, 7 H, CH2CH2CH2O, CH2CHCHOH, 1 H of CH2–
CHCH=) ppm. 13C NMR (75 MHz, CDCl3): δ = 167.0, 161.2,
150.4, 133.5, 131.5, 130.9, 129.4, 119.9, 113.9, 95.3, 76.7, 72.7, 70.5,
IR (film): ν = 2933, 2856, 1734, 1612, 1513, 1437, 1248, 1099, 1039,
˜
970, 918, 821, 758 cm–1. HRMS (ESI): calcd. for C23H34O6Na [M
+ Na]+ 429.2253; found 429.225.
{(1R,2S,4S)-2-[(E)-6-(4-Methoxybenzyloxy)hex-1-enyl]-4-(methoxy-
methoxy)cyclopentyl}methanol (43): The alcohol 43 was prepared
by a procedure similar to that described above for 36, starting from
the ester 6b (890 mg, 2.2 mmol). Compound 43 was isolated as a
colourless oil (741 mg, 89% yield) after purification of the crude
product by silica gel chromatography (EtOAc/petroleum ether 1:1).
70.1, 55.4, 51.7, 48.6, 43.4, 40.5, 32.4, 29.4, 26.2 ppm. IR (film): ν
˜
= 3447, 2934, 2856, 1723, 1657, 1612, 1513, 1437, 1248, 1099, 1039,
980, 917, 821, 735 cm–1. HRMS (CI): calcd. for C26H38O7 [M +
H]+ 463.2696; found 463.269.
1
[α]2D0 = –14.8 (c = 0.5, CHCl3). H NMR (300 MHz, CDCl3): δ =
Data for 46: [α]2D0 = –17.9 (c = 0.5, CHCl3). H NMR (300 MHz,
1
7.24 (d, J = 6.6 Hz, 2 H, Ar-H), 6.86 (d, J = 6.6 Hz, 2 H, Ar-H),
5.39 (m, 2 H, CH=CH), 4.61 (s, 2 H, CH2 MOM), 4.41 (s, 2 H, CDCl3): δ = 7.24 (d, J = 6.9 Hz, 2 H, Ar-H), 6.87 (dd, J = 4.8,
OCH2–Ar), 4.12 (m, 1 H, CH–O), 3.79 (s, 3 H, ArOCH3), 3.50 and
3.64 (ABX system, J = 5.1, 5.7, 10.5 Hz, 2 H, CH2OH), 3.42 (t, J
= 6.54 Hz, 2 H, CH2CH2O), 3.34 (s, 3 H, MOM), 1.84–2.26 (m, 6
15.6 Hz, 1 H, =CH–CHOH), 6.86 (d, J = 6.9 Hz, 2 H, Ar-H), 6.03
(d, J = 15.6 Hz, 1 H, =CH–CO2Me), 5.45 (m, 2 H, CH=CH), 4.59
(s, 2 H, CH2 MOM), 4.41 (s, 2 H, OCH2–Ar), 4.27 (m, 1 H,
1376
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Eur. J. Org. Chem. 2010, 1364–1380