B. Vaz, A. R. de Lera et al.
(1.5 mL). After stirring for 3 h at 258C, EtOAc was added. The organic
layer was washed with H2O (3ꢅ) and dried (Na2SO4) and the solvent was
evaporated. The residue was purified by column chromatography (silica
C18, CH3CN) to afford a colorless oil (0.11 g, 60%) identified as C14-
silane 39b and diethyl (2Z,3Z)-2,3-bis(trimethylsilylmethylidene)succi-
nate (40) (0.032 g, 16%) as a yellow oil.
(s, 3H; CH3), 0.98 (s, 9H; 3ꢅCH3), 0.06 (s, 3H; CH3), 0.05 ppm (s, 3H;
CH3); 13C NMR (100 MHz, C6D6, 258C): d=166.4 (s), 141.6 (s), 138.4
(d), 131.5 (d), 130.1 (d), 120.1 (s), 114.6 (d), 102.0 (s), 85.7 (s), 70.2 (s),
67.2 (s), 65.2 (d), 60.9 (t), 59.1 (t), 47.7 (t), 41.9 (t), 35.4 (s), 29.4 (q), 26.1
(q, 3ꢅ), 25.3 (q), 20.1 (q), 18.3 (s), 17.3 (q), 14.4 (q), À4.6 ppm (q, 2ꢅ);
À
À
À
IR (NaCl): n˜ =3600–3000 (br, O H), 2956 (s, C H), 2928 (s, C H), 2856
(m, CH), 2181 (w, C C), 1722 (s, C=O), 1379 (s), 1084 cmÀ1(s); MS
Data for C14-silane 39b: [a]2D5 =À61.60 cm3 gÀ1 dmÀ1 (c=0.7 in MeOH);
1H NMR (400 MHz, C6D6, 258C): d=6.65 (dd, J=15.6, 0.8 Hz, 1H; H8),
6.43 (d, J=15.6 Hz, 1H; H7), 6.08 (s, 1H; H10), 4.09–3.94 (m, 3H; H3 +
CO2CH2CH3), 2.28 (app. ddd, J=14.4, 5.1, 1.7 Hz, 1H; H4A), 1.63 (dd,
J=14.4, 8.3 Hz, 1H; H4B), 1.59 (app. ddd, J=13.1, 3.4, 1.6 Hz, 1H; H2A),
1.28 (dd, J=13.0, 10.0 Hz, 1H; H2B), 1.14 (s, 3H; CH3), 1.11 (s, 3H;
CH3), 1.09 (s, 3H; CH3), 0.98 (s, 9H; 3ꢅCH3), 0.97 (s, 3H; CH3), 0.19 (s,
9H; 3ꢅCH3), 0.06 (s, 3H; CH3), 0.05 ppm (s, 3H; CH3); 13C NMR
(100 MHz, C6D6, 258C): d=167.8 (s), 146.0 (s), 141.0 (d), 133.2 (d), 129.7
(d), 70.0 (s), 66.9 (s), 65.2 (d), 60.7 (t), 47.8 (t), 42.0 (t), 35.5 (s), 29.5 (q),
26.1 (q, 3ꢅ), 25.3 (q), 20.2 (q), 18.3 (q), 14.2 (q), À0.4 (q, 3ꢅ), À4.5 ppm
ꢀ
(ESI+): m/z (%): 511 [M+Na+] (14), 489 [M+H+] (100); HRMS (ESI+):
m/z: calcd for C28H45O5Si: 489.3031 [M+H]+; found: 489.3043.
C20-lactone 43: A solution of alcohol 42b (0.02 g, 0.041 mmol) in ethanol
(0.20 mL) was added to a mixture of a 2n aqueous solution of KOH
(0.16 mL) and ethanol (0.66 mL) at 708C. After stirring for 30 min at
708C, the reaction was cooled down to 08C and diethyl ether was added.
The pH was adjusted to 7 with DOWEX 50WX8, the mixture was fil-
tered through a pad of Celite (Et2O) and the solvent was evaporated.
The crude was purified by crystallization (hexane/Et2O) to afford a white
solid identified as C20-acid 23 (16.4 mg, 87%). 1H NMR (400 MHz,
CDCl3, 258C): d=6.40 (d, J=15.7 Hz, 1H; H7), 6.28 (d, J=15.6 Hz, 1H;
H8), 6.10 (s, 1H; H10), 6.06 (t, J=6.4 Hz, 1H; H14), 4.26 (d, J=6.7 Hz,
2H; H15), 3.87–3.80 (m, 1H; H3), 2.24 (dd, J=14.4, 5.1 Hz, 1H; H4A),
1.85 (s, 3H; CH3), 1.64 (dd, J=14.4, 8.3 Hz, 1H; H4B), 1.54–1.45 (m, 1H;
H2A), 1.30–1.18 (m, 1H: H2B), 1.17 (s, 3H; CH3), 1.12 (s, 3H; CH3), 0.95
(s, 3H; CH3), 0.87 (s, 9H; 3ꢅCH3), 0.04 ppm (s, 6H; 2ꢅCH3).
À
À
À
(q); IR (NaCl): n˜ =2956 (m, C H), 2929 (m, C H), 2857 (w, C H), 1724
(s, C=O), 1250 cmÀ1(s); MS (ESI+): m/z (%): 489 [M+Na+] (13), 467
[M+H+] (100); HRMS (ESI+): m/z: calcd for C25H47O4Si2: 467.3007
[M+H]+; found: 467.3021.
Data for 40: 1H NMR (400 MHz, C6D6, 258C): d=6.54 (s, 2ꢅ1H), 3.96
(q, J=7.1 Hz, 4H; 2ꢅCO2CH2CH3), 0.93 (t, J=7.1 Hz, 6H, 2ꢅ
CO2CH2CH3), 0.32 ppm (s, 18H, 6ꢅCH3); 13C NMR (100 MHz, C6D6,
258C): d=166.7 (s, 2ꢅ), 149.1 (s, 2ꢅ), 146.5 (d, 2ꢅ), 60.8 (t, 2ꢅ), 14.1 (q,
AgNO3 (0.008 g, 0.048 mmol) was added to a solution of acid 23 (0.004 g,
8.7·10À3 mmol) in MeOH (0.4 mL). After stirring for 1 h at 258C, the re-
action mixture was filtered through a pad of silica gel (hexane/EtOAc)
and the solvent was evaporated to afford a pale-yellow solid (0.004 g,
100%) identified as C20-lactone 43. M.p. 139–1408C (hexane/EtOAc);
À
2ꢅ), À0.3 ppm (q, 6ꢅ); IR (NaCl): n˜ =2957 (m, C H), 1726 (s, C=O),
854 cmÀ1 (s); MS (ESI+): m/z (%): 365 (100) [M+Na+], 343 (46) [M+H+
], 297 (11), 249 (8); HRMS (ESI+): m/z: calcd for C16H31O4Si2: 343.1755
[M+H]+; found: 343.1748.
1
[a]2D4 =À64.1 cm3 gÀ1 dmÀ1 (c=0.1 in MeOH); H NMR (400 MHz, CDCl3,
258C): d=7.19 (d, J=15.6 Hz, 1H; H7), 7.03 (s, 1H; H10), 6.35 (d, J=
15.5 Hz, 1H; H8), 5.96 (tq, J=6.6, 1.0 Hz, 1H; H14), 5.64 (s, 1H; H12),
4.35 (d, J=6.6 Hz, 2H; H15), 3.85 (dddd, J=10.1, 8.4, 5.1, 3.4 Hz, 1H;
H3), 2.25 (app. ddd, J=14.5, 5.1, 1.6 Hz, 1H; H4A), 2.09 (d, J=0.9 Hz,
3H; C13-CH3), 1.69–1.65 (m, 1H; H4B), 1.51 (app. ddd, J=13.2, 3.4,
1.6 Hz, 1H; H2A), 1.27–1.24 (m, 1H; H2B), 1.18 (s, 3H; C1-CH3), 1.17 (s,
3H; C5-CH3), 0.94 (s, 3H; C1-CH3), 0.88 (s, 9H; 3ꢅCH3), 0.05 (s, 3H;
CH3), 0.045 ppm (s, 3H; CH3); 13C NMR (100 MHz, CDCl3, 258C): d=
168.8 (s), 146.8 (s), 137.0 (d), 136.9 (d), 134.8 (d), 134.2 (s), 126.2 (s),
121.4 (d), 117.7 (d), 70.7 (s), 67.7 (s), 64.8 (d), 59.7 (t), 47.1 (t), 41.5 (t),
35.3 (s), 29.6 (q), 26.0 (q), 25.1 (q), 20.2 (q), 18.3 (s), 15.7 (q), À4.57 (q),
C14-iodide 41b: 2,6-Lutidine (0.013 mL, 0.11 mmol) and NIS (0.054 g,
0.24 mmol) were added to a cooled (08C) solution of silane 39b (0.074 g,
0.16 mmol) in (HFIP, 1.6 mL). After the reaction mixture had been stir-
red for 2.5 h at 08C, water and Et2O were added, the layers were separat-
ed, and the organic layer was washed with a saturated aqueous solution
of Na2S2O3 (1ꢅ), water (1ꢅ), and
a saturated aqueous solution of
NaHCO3 (1ꢅ), dried (Na2SO4), and the solvent was evaporated. The resi-
due was purified by column chromatography (silica C18, CH3CN) to
afford a pale-yellow oil (0.068 g, 81%) identified as C14-iodide 41b.
1
[a]D25 =À58.20 cm3 gÀ1 dmÀ1 (c=0.9 in MeOH); H NMR (400 MHz, C6D6,
258C): d=6.30 (d, J=15.7 Hz, 1H; H8), 6.16 (d, J=15.7 Hz, 1H; H7),
6.04 (s, 1H; H10), 4.18–4.09 (m, 2H; CO2CH2CH3), 3.97 (dddd, J=9.9,
8.3, 5.0, 3.4 Hz, 1H; H3), 2.25 (app. ddd, J=14.4, 5.1, 1.7 Hz, 1H; H4A),
1.60 (dd, J=14.4, 8.2 Hz, 1H; H4B), 1.55 (app. ddd, J=11.4, 3.2, 1.6 Hz,
1H; H2A), 1.25 (dd, J=13.0, 10.0 Hz, 1H; H2B), 1.06 (s, 3H; C5-CH3),
1.05 (s, 3H; C1-CH3), 1.02 (s, 3H; C1-CH3), 1.01 (s, 3H; CO2CH2CH3),
0.98 (s, 9H; 3ꢅCH3), 0.06 (s, 3H; CH3), 0.05 ppm (s, 3H; CH3);
13C NMR (100 MHz, C6D6, 258C): d=167.0 (s), 145.6 (s), 130.3 (d), 130.1
(d), 82.6 (d), 69.9 (s), 67.0 (s), 65.1 (d), 61.0 (t), 47.6 (t), 41.8 (t), 35.2 (s),
29.3 (q), 26.1 (q, 3ꢅ), 25.2 (q), 20.0 (q), 18.3 (s), 14.2 (q), À4.6 ppm (q,
À
À4.61 ppm (q); IR (NaCl): n˜ =3700–3500 (br, OH), 2955 (s, C H), 2927
À1(s, C=O); MS (ESI+): m/z (%): 483
(s, C H), 2855 (s, C H), 1757 cm ACHTGNURTENNUGN
À
À
(19) [M+Na+], 461 (100) [M+H+]; HRMS (ESI+): m/z: calcd for
C26H41O5Si: 461.2718 [M+H+]; found: 461.2728.
C20-alcohol 29: A cooled (08C) mixture of THF/HCO2H/H2O (2.7 mL,
6:3:1 ratio) was added to a cooled (08C) flask containing C20-lactone 43
(0.029 g, 0.063 mmol). After stirring for 6 h at 08C, EtOAc was added
and the reaction mixture was neutralized at 08C with a saturated aqueous
solution of NaHCO3. The aqueous layer was extracted with EtOAc (3ꢅ),
the organic layer was dried (Na2SO4), and the solvent was evaporated.
The residue was purified by column chromatography (silica gel, from
95:5 to 90:10 CH2Cl2/MeOH) to afford a yellow solid (0.016 g 74%)
identified as C20-alcohol 29.
À
À
À
2ꢅ); IR (NaCl): n˜ =2956 (s, C H), 2928 (s, C H), 2856 (m, C H), 1733
(s, C=O), 1183 cmÀ1(s); HRMS (ESI+): m/z: calcd for C22H38IO4Si:
521.1579 [M<M+H]+; found: 521.1575.
C20-alcohol 42b: Alkyne 14 (0.018 g, 0.19 mmol), [PdACTHNUGTRNEUG(N PPh3)4] (0.014 g,
0.012 mmol), and CuI (0.002 g, 0.012 mmol) were sequentially added to a
stirred solution of iodide 41b (0.065 g, 0.13 mmol) in iPr2NH (1.5 mL) at
258C. After stirring for 1 h at 258C, the reaction mixture was poured into
a saturated aqueous solution of NH4Cl and the mixture was extracted
with EtOAc (3ꢅ). The combined organic layers were washed with brine,
dried (Na2SO4), and the solvent was evaporated. The residue was purified
by column chromatography (silica-NH2, 85:15 hexane/EtOAc) to afford a
C20-aldehyde 18: Na2CO3 (0.40 g, 4.14 mmol) and MnO2 (0.44 g,
4.14 mmol) were added to a cooled solution of C20-alcohol 29 (0.080 g,
0.23 mmol) in CH2Cl2 (27.0 mL). After stirring for 30 min at 08C, the re-
action mixture was filtered through a pad of Celite (80:20, CH2Cl2/
MeOH) and the solvent was evaporated to afford a yellow solid (0.079 g,
93%) identified as C20-aldehyde 18, which was used without further puri-
fication. [a]D25 =À85.5 cm3 gÀ1 dmÀ1 (c=0.3 in CHCl3); 1H NMR
(400 MHz, CDCl3, 258C): d=10.12 (d, J=8.0 Hz, 1H; H15), 7.29 (d, J=
15.8 Hz, 1H; H7), 7.07 (s, 1H; H10), 6.42 (d, J=15.8 Hz, 1H; H8), 6.14 (d,
J=8.0 Hz, 1H; H14), 5.72 (s, 1H; H12), 3.96–3.86 (m, 1H; H3), 2.55 (s,
3H; C13-CH3), 2.45–2.34 (m, 1H; H4A), 1.69–1.59 (m, 2H; H4B +H2A),
1.31–1.23 (m, 1H; H2), 1.20 (s, 3H; CH3), 1.19 (s, 3H; CH3), 0.96 ppm (s,
3H; CH3); 13C NMR (100 MHz, CDCl3, 258C): d=191.2 (d), 167.7 (s),
151.7 (s), 137.1 (d), 136.1 (d), 132.8 (d), 128.8 (s), 121.3 (d), 115.4 (d),
77.4 (s), 70.5 (s), 67.9 (s), 64.2 (d), 47.0 (t), 40.9 (t), 35.4 (s), 29.6 (q), 25.1
colorless oil (0.047 g, 77%) identified as C20-alcohol 42b. [a]D26
=
À67.7 cm3 gÀ1 dmÀ1 (c=1.2 in MeOH); 1H NMR (400 MHz, C6D6, 258C):
d=6.52 (d, J=15.6 Hz, 1H; H7 or H8), 6.47 (d, J=15.6 Hz, 1H; H7 or
H8), 6.04 (tq, J=6.5, 1.5 Hz, 1H; H14), 5.73 (s, 1H; H10), 4.21–4.07 (m,
2H; CO2CH2CH3), 3.98 (dddd, J=10.0, 8.4, 5.0, 3.3 Hz, 1H; H3), 3.83 (d,
J=6.6 Hz, 2H; 2H15), 2.27 (app. ddd, J=14.4, 5.1, 1.6 Hz, 1H; H4A),
1.65–1.54 (m, 2H; H2A +H4B), 1.61 (s, CH3), 1.27 (dd, J=13.0, 10.1 Hz,
1H; H2B), 1.09 (s, 3H; CH3), 1.08 (s, 3H; CH3), 1.07 (s, 3H; CH3), 1.06
&
8
&
ꢂ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 0000, 00, 0 – 0
ÝÝ
These are not the final page numbers!