F. Fache et al. / Tetrahedron 61 (2005) 5261–5266
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from 1c and 3a: isolated yield 41%; oil; 1H NMR
(300 MHz, CDCl3) d: 0.16 (s, 6H), 1.01 (s, 9H), 3.72 (s,
2H), 3.81 (s, 3H), 3.93 (s, 6H), 4.83 (s, 2H), 6.40 (d, JZ
15.5 Hz, 1H), 6.69–7.18 (m, 6H), 7.70 (d, JZ15.5 Hz, 1H);
13C NMR (75 MHz, CDCl3) d: K4.2 (CH3–Si), 18.8 (C),
26.1 (CH3), 46.7 (CH2), 55.9, 56.3 and 56.4 (OCH3), 67.7
(CH2), 110.0, 111.4, 114.8, 121.5, 122.2 and 123.3 (CH),
126.5 (C), 127.5 (C), 146.5 (CH), 151.6 (C), 151.8 (C]O),
202.4 (C]O).
from 9b: isolated yield 32%; mpZ113–115 8C; H NMR
(300 MHz, CDCl3) d: 3.66 (s, 2H), 3.81 (s, 3H), 3.85 (s, 3H),
4.80 (s, 2H), 6.32 (d, JZ15.8 Hz, 1H), 6.67–7.03 (m, 6H),
7.63 (d, JZ15.8 Hz, 1H); 13C NMR (75 MHz, CDCl3) d:
46.3 (CH2), 56.1 (OCH3), 67.7 (CH2), 109.8, 112.1, 114.1,
115.0, 115.1, 122.5, 123.6, 124.7 (CH), 126.8 and 145.2 (C),
146.6 (CH), 147.1 and 148.6 (C), 166.7 (C]O), 202.5
(C]O); CI-LRMS m/z 373 (MCHC%), 372 (MC%), 195,
177; CI-HRMS calcd for C20H21O7 (MCHC%) 373.1287,
found 373.1288.
4.6.5. Synthesis of 9e. According to the general procedure
from 1c and 3b: this product turned out to be very unstable
and therefore was immediately engaged in the following
step without purification to give 10e after deprotection.
4.7.3. Synthesis of 10c. According to the general procedure
from 9c: isolated yield 26%; mpZ99–100 8C; H NMR
1
(300 MHz, CDCl3CCD3OD) d: 3.64 (s, 2H), 3.78 (s, 3H),
4.75 (s, 2H), 6.27 (d, JZ15.8 Hz, 1H), 6.63–6.78 (m, 5H),
7.34 (d, JZ8.5 Hz, 1H), 7.64 (d, JZ15.8 Hz, 1H); 13C
NMR (75 MHz, CDCl3CCD3OD) d: 46.2 (CH2), 56.0
(OCH3), 67.6 (CH2), 112.3, 113.2, 115.2, 116.1, 122.4 and
124.5 (CH), 126.0, 130.4 and 145.3 (C), 146.8 (CH), 147.4
and 159.7 (C), 167.1 (C]O), 203.1 (C]O); EI-LRMS m/z
342 (MC%), 205, 147, 137; EI-HRMS calcd for C19H18O6
(MC%) 342.1103, found 342.1105.
4.6.6. Synthesis of 9f. According to the general procedure
from 1b and 3b: isolated yield 66%; oil; 1H NMR
(300 MHz, CDCl3) d: 0.17 (s, 6H), 0.18 (s, 6H), 0.2 (s,
6H), 0.97 (s, 27H), 3.63 (s, 2H), 4.76 (s, 2H), 6.36 (d, JZ
15.8 Hz, 1H), 6.63–6.89 (m, 5H), 7.41 (d, JZ8.4 Hz, 2H),
7.68 (d, JZ15.8 Hz, 1H); 13C NMR (75 MHz, CDCl3) d:
K3.9 and K3.7 (CH3–Si), 18.6 and 18.8 (C), 26.0 and 26.3
(CH3), 46.4 (CH2), 67.7 (CH2), 114.8 (CH), 120.9 (CH),
121.7 (CH), 122.7 (CH), 126.2 (C), 127.9 (C), 130.2 (CH),
146.3 (CH), 146.7 (C), 147.4 (C), 166.7 (C), 175.7 (C),
202.4 (C]O).
4.7.4. Synthesis of 10d. According to the general procedure
from 9d: isolated yield 45% (oil); 1H NMR (300 MHz,
CDCl3) d: 3.71 (s, 2H), 3.86 (s, 3H),3.91 (s, 6H), 4.84 (s,
2H), 6.40 (d, JZ15.8 Hz, 1H), 6.72–6.88 (m, 4H), 7.10 (m,
2H), 7.7 (d, JZ15.8 Hz, 1H); 13C NMR (75 MHz, CDCl3C
CD3OD) d: 46.24 (CH2), 56.3 (CH3), 67.8 (CH2), 110.1,
111.4, 112.2, 114.7, 115.1, 122.7 and 123.4 (CH), 124.9,
127.5 and 145.4 (C), 146.6 (CH), 147.2, 149.6 and 151.8
(C), 166.7 (C]O), 202.6 (C]O); EI-LRMS m/z 386 (MC%),
249, 208, 191(100), 163, 137; EI-HRMS calcd for C21H22O7
(MC%) 386.1365, found 386.1369.
4.6.7. Synthesis of 9g. According to the general procedure
from 1d and 3a: isolated yield 70%; oil; 1H NMR
(300 MHz, CDCl3) d: 0.15 (s, 6H), 1.00 (s, 9H), 3.71 (s,
2H), 3.79 (s, 3H), 4.82 (s, 2H), 6.52 (d, JZ15.8 Hz, 1H),
6.68 (m, 2H), 6.85 (d, JZ8.4 Hz, 1H), 7.39 (m, 3H), 7.53
(m, 2H), 7.76 (d, JZ15.8 Hz, 1H); 13C NMR (75 MHz,
CDCl3) d: K4.2 (CH3–Si), 18.8 (C), 26.1 (CH3), 46.7
(CH2), 55.9 (OCH3), 67.8 (CH2), 113.5, 117.2, 121.5, 122.2
and 128.6 (CH), 129.3 (C), 131.0 (CH), 146.6 (CH), 150.0
(C), 151.6 (C), 166.4 (C]O), 202.3 (C]O).
4.7.5. Synthesis of 10e. According to the general procedure
from 9e (see above): isolated yield 12% in two steps; H
1
NMR (300 MHz, CDCl3CCD3OD) d: 3.40 (s, 2H), 3.66 (s,
6H), 4.59 (s, 2H), 6.14 (d, JZ15.8 Hz, 1H), 6.33–6.91 (m,
6H), 7.46 (d, JZ15.8 Hz, 1H); 13C NMR (75 MHz,
CDCl3CCD3OD) d: 46.2 (CH2), 57.6 (OCH3), 62.3
(CH2), 111.6, 112.8, 115.8, 117.2, 118.0, 122.6 (CH),
124.7, 125.9, 128.8, 145.8 and 146.7 (C),148.0 (CH), 150.8
(C]O), 204.9 (C]O); CI-LRMS m/z 373 (MCHC%), 355,
209 (100), 191, 165; CI-HRMS calcd for C20H21O7 (MC
4.7. Deprotection of the silyl ethers20
To a diluted solution of silyl ether in acetonitrile (0.2 M)
was added carefully aqueous HF (48–51%) (two volumes of
CH3CN for one volume HFaq). The solution was stirred at
room temperature for 30 min and then aqueous NaOH (8%)
was added. The organic phase was extracted with CH2Cl2,
dried over MgSO4, concentrated and the crude product was
purified by flash column chromatography on silica gel
(petroleum ether/ethyl acetate 1:1).
H
C%) 373.1287, found 373.1285.
4.7.6. Synthesis of 10f. According to the general procedure
1
from 9f: isolated yield 30%; mpZ172–177 8C; H NMR
4.7.1. Synthesis of cimiracemate B 10a.6 According to the
general procedure from 9a: isolated yield 10%; H NMR
(300 MHz, CDCl3CCD3OD) d: 3.59 (s, 2H), 3.78 (s, 3H),
4.76 (s, 2H), 6.28 (d, JZ15.8 Hz, 1H), 6.53–6.80 (m, 5H),
7.36 (m, 2H), 7.62 (d, JZ15.8 Hz, 1H); 13C NMR (75 MHz,
CDCl3CCD3OD) d: 46.0 (CH2), 67.5 (CH2), 113.1, 115.6,
115.9, 116.3 and 121.2 (CH), 124.5 and 125.8 (C), 130.3
(CH), 144.2 and 145.0(C), 146.7 (CH), 159.8 (C), 167.2
(C]O), 203.4 (C]O); CI-LRMS m/z 329 (MCHC%), 183,
1
(300 MHz, CD3OD) d: 3.69 (s, 2H), 3.90 (s, 3H), 4.87 (s,
2H), 6.43 (d, JZ15.8 Hz, 1H), 6.60–6.84 (m, 4H), 7.08–
7.21 (m, 2H), 7.66 (d, JZ15.8 Hz, 1H); 13C NMR (75 MHz,
CD3OD) d: 46.6 (CH2), 56.7 (CH3), 68.8 (CH2), 112.1,
114.8, 116.2, 116.8, 117.9, 122.3 and 124.3 (CH), 124.6,
126.3, 127.9, 128.1 and 145.9 (C), 146.8 (CH), 147.2, 148.0,
149.7and 151.1 (C), 168.6 (C]O), 204.9 (C]O); CI-
LRMS m/z 359 (MCHC%), 313, 235, 217, 195 (100), 177,
167; CI-HRMS calcd for C19H19O7 (MCHC%) 359.1131,
found 359.1133.
165, 147; CI-HRMS calcd for C18H17O6 (MCHC%
)
329.1025, found 329.1025.
4.7.7. Synthesis of 10g. According to the general procedure
from 9g: isolated yield 44%; PF 1H NMR (300 MHz,
CDCl3) d 3.64 (s, 2H), 3.88 (s, 3H), 4.83 (s, 2H), 6.52 (d, JZ
15.9 Hz, 1H), 6.74 (m, 2H), 6.87 (m, 1H), 7.41 (m, 3H), 7.53
4.7.2. Synthesis of 10b. According to the general procedure