5402
T.-Z. Liu, M. Isobe / Tetrahedron 56 (2000) 5391±5404
To
a
solution of the ole®n intermediate (30 mg,
for 20 min, the mixture was poured into a cold saturated
NH4Cl solution, and extracted with CH2Cl2 (£3), dried
over Na2SO4 and concentrated. The residue was dissolved
in THF (0.5 mL) and treated with TBAF (1.0 M in THF,
0.05 mL) at 08C for 5 min. The reaction mixture was poured
into sat. NaHCO3 solution, extracted with CH2Cl2 (£3). The
organic layer was dried over Na2SO4 and concentrated. The
residue was puri®ed by silica gel chromatography (ether/
hexane3:1) to afford 29 (47 mg, 92%) as a white solid.
0.024 mmol) in MeOH (0.5 mL) was added 5% sodium
amalgam (110 mg, 0.24 mmol). The mixture was stirred at
room temperature overnight. The resulting mixture was
®ltered through Supper Cell and concentrated. The residue
was puri®ed by silica gel chromatography (ether/
hexane1:10) to afford 27 (20 mg, 89%) as a colorless
1
oil. H NMR (400 MHz, CDCl3) d 1.06 (9H, s, tert-Bu),
1.07 (9H, s, tert-Bu), 1.20 (3H, d, J7.0 Hz, Me), 1.71
(2H, dt, J9.5, 3.5 Hz, H-50£2), 2.45 (1H, m, H-46), 2.88
(1H, dd, J8.5, 8.0 Hz, H-45), 3.61 (1H, dd, J10.0,
5.2 Hz, H-40a), 3.69±3.76 (4H, m, H-44, H-52£2, H-40b),
3.84 (1H, m, H-51), 4.15±4.21 (2H, m, H-41, H-49), 4.50
(1H, d, J11.5 Hz, PhCH2O), 4.78 (1H, d, J11.5 Hz,
PhCH2O), 5.43 (1H, dt, J12.0, 2.5 Hz, H-47), 5.52 (1H,
dt, J12.0, 2.5 Hz, H-48), 5.59 (1H, dt, J10.2, 2.0 Hz,
H-43), 5.82 (1H, dt, J10.2, 1.5 Hz, H-42), 7.30±7.72
(25H, m, Ph£5). 13C NMR (75 MHz, CDCl3) d 18.6, 19.1,
26.7, 26.8, 38.9, 66.5, 66.9, 72.8, 74.4, 75.6, 76.2, 78.0,
79.6, 127.7, 128.1, 128.5, 129.7, 133.6, 133.7, 134.2,
134.8, 135.7, 138.9. Anal. calcd for C25H32O7: C, 67.55;
H, 7.26. Found: C, 67.43; H, 7.28.
1
Mp: 131±1338C. H NMR (300 MHz, CDCl3) d 1.02 (3H,
d, J7.0 Hz, Me), 1.07 (9H, s, tert-Bu), 1.38±1.47 (5H, m,
H-35, H-38, H-40a, H-43, H-50a), 1.57±1.64 (2H, m,
H-34£2), 1.72±1.83 (4H, m, H-38, H-39, H-40b, H-50b),
1.95±2.01 (1H, m, H-35), 2.29 (1H, m, H-43), 2.41 (1H, d,
J6.0 Hz, OH), 2.91 (1H, dt, J10, 3 Hz, H-37), 3.01±3.08
(2H, m, H-36, H-41), 3.10±3.14 (3H, m, H-42, H-44, H-51),
3.19 (total 3H, two s, OMe), 3.26 (1H, m, H-33), 3.39 (1H,
dd, J10.2, 4.0 Hz, CH2SO2Ph), 3.49 (1H, dd, J10.2,
6.8 Hz, CH2SO2Ph), 3.63±3.75 (3H, m, H-45, H-52£2),
3.81 (1H, br d, J11.8 Hz, H-33), 3.96 (1H, dd, J9.8,
3.5 Hz, H-49), 4.45 (1H, d, J12.0 Hz, PhCH2O), 4.71
(1H, d, J12.0 Hz, PhCH2O), 7.30±7.92 (20H, m, Ph£4).
13C NMR (75 MHz, CDCl3) d 14.1, 19.3, 25.9, 26.9, 27.7,
28.8, 29.7, 32.8, 38.6, 41.7, 45.2, 46.2, 56.1, 57.4, 66.6,
67.2, 67.3, 67.5, 72.7, 75.9, 80.4, 81.0, 81.5, 81.7, 82.4,
83.6, 84.6, 127.6, 127.7, 127.9, 128.1, 128.4, 129.3, 129.7,
133.5, 135.7, 138.8, 139.7. Anal. calcd for C52H66O8SSi: C,
71.03; H, 7.57. Found: C 69.96; H, 7.64.
Acetic acid 6-(3-acetoxy-2-benzyloxypropyl)-9-methyl-
4a,6,9,9a-tetrahydro-2H-1,5-dioxabenzocyclohepten-2-
ylmethyl ester (28). A solution of 27 (15 mg, 0.02 mmol) in
THF (0.5 mL) was treated with TBAF (1.0 M in THF,
0.02 mL) at room temperature for 1 h. The mixture was
concentrated and the residue was puri®ed by silica gel
(ether/hexane10:1, Rf0.19) to afford diol intermediate
(6.6 mg, 98%). The diol was dissolved in CH2Cl2
(0.3 mL) and treated with Ac2O (0.1 mL), and pyridine
(0.15 mL) at room temperature for 30 min. The mixture
was diluted with CH2Cl2 (5 mL) and washed with 1 N
HCl, saturated NaHCO3 (£3) and brine. Concentration of
the solvent and the residue was puri®ed by silica gel chro-
matography (ether/hexane1:1, Rf0.15) to afford 28
(8.1 mg, 100%) as a colorless oil. [a]2D52103.7 (c 0.40,
CHCl3). 1H NMR (400 MHz, CDCl3) d 1.20 (3H, d,
J7.0 Hz, Me), 1.75 (2H, dt, J9.8, 4.0 Hz, H-50£2),
2.08 (3H, s, MeCO), 2.10 (3H, s, MeCO), 2.49 (1H, m,
H-46), 2.89 (1H, dd, J9.2, 8.5 Hz, H-45), 3.74 (1H, ddd,
J9.2, 3.5, 1.5 Hz, H-44), 3.92 (1H, J12.5, 4.8 Hz, H-51),
4.05±4.13 (3H, m, H-52a, H-40£2), 4.21 (1H, ddd, J10, 5,
3 Hz, H-49), 4.28 (1H, m, H-41), 4.31 (1H, dd, J12.0,
4.2 Hz, H-52b), 4.51 (1H, d, J11.8 Hz, PhCH2O), 4.73
(1H, d, J11.8 Hz, PhCH2O), 5.45 (1H, dt, J12.0,
2.4 Hz, H-47), 5.55 (1H, dt, J12.0, 3.0 Hz, H-48), 5.64
(1H, d, J10 Hz, CHvCH), 5.68 (1H, d, J10 Hz,
CHvCH), 7.28±7.36 (5H, m, Ph). 13C NMR (100 MHz,
CDCl3) d 18.7, 20.9, 29.7, 38.9, 39.3, 65.9, 66.1, 72.4,
73.1, 74.3, 77.6, 79.7, 126.9, 127.9, 128.1, 128.5, 130.8,
133.7, 134.9, 138.2, 170.8, 170.9. HRMS (EI): calcd for
C25H33O7: m/z 445.2148 (M1H), found: 445.2131.
Compound (30). To a solution of 29 (42 mg, 0.048 mmol)
in degassed CH2Cl2 (2 mL) was added a solution of bis-
cobaltoctacarbonyl (30 mg, 0.086 mmol) in degassed
CH2Cl2 (0.5 mL) at 08C. After stirring at room temperature
for 1 h, the mixture was concentrated and the residue was
puri®ed by silica gel chromatography (ether/hexane1:2) to
afford cobalt complex 30 (49 mg, 87%). 1H NMR
(300 MHz, CDCl3) d 1.05 (3H, d, J7.0 Hz, Me), 1.26±
1.35 (3H, m, H-35a, H-38a, H-40a), 1.36±1.44 (1H, m,
H-50a), 1.45±1.55 (2H, m, H-43a, H-50b), 1.56±1.62 (2H,
m, H-34£2), 1.69±1.84 (3H, m, H-38b, H-40b, H-39),
1.95±2.03 (2H, m, H-35b, H-43b), 2.80 (1H, td, J10.0,
2.6 Hz, H-37), 2.91 (1H, td, J10.0, 4.5 Hz, H-36), 2.98
(1H, m, H-45), 3.05 (1H, td, J10.0, 5.0 Hz, H-42), 3.29
(2H, m, H-41, CH2SO2Ph), 3.37 (1H, dd, J9, 3 Hz, H-33a),
3.44 (3H, s, OMe), 3.68 (1H, dd, J11, 5 Hz, H-52a), 3.76
(1H, dd, J11, 3 Hz, H-52b), 3.81±3.86 (4H, m, H-33b,
H-44, H-46, H-51), 4.04 (1H, dd, J15, 10 Hz, CH2SO2Ph),
4.40 (1H, d, J11.2 Hz, OCH2Ph), 4.55 (1H, d, J10 Hz,
H-49), 4.86 (1H, d, J11.2 Hz, OCH2Ph), 7.36±7.91 (20H,
m, Ph£4). 13C NMR (75 MHz, CDCl3) d 14.0, 19.1, 22.6,
26.1, 26.7, 27.4, 28.1, 31.5, 32.7, 37.0, 41.3, 42.5, 45.4,
45.9, 59.1, 59.8, 65.1, 67.5, 73.3, 77.6, 79.0, 80.5, 81.2,
82.2, 84.8, 95.1, 98.5, 128.0, 128.2, 128.5, 128.8, 129.1,
129.4, 129.9, 133.2, 135.7, 137.7, 139.3, 199.5, 200.5.
3-[1-Benzenesulfonylmethyl-6-benzyloxy-7-(tert-butyl-
diphenylsilyloxy)-4-methoxyhept-2-ynyl]-6-methyldode-
cahydro-4,8,12-trioxadibenzo[a,d]cycloocten-2-ol (29).
A solution of acetylene 23 (128 mg, 0.27 mmol) in THF
(1 mL) was cooled to 08C and treated with n-BuLi (1.5 M
in hexane, 0.15 mL, 0.22 mmol) for 15 min. A solution of
compound 21 (34 mg, 0.054 mmol) in THF (0.7 mL) was
added dropwise to the reaction mixture at 08C. After stirring
Compound (31). A solution of 30 (46 mg, 0.039 mmol) in
degassed CH2Cl2 (4 mL) was treated with a solution of
0.16 M BF3´OEt2 in CH2Cl2 at 08C for 50 min under argon
atmosphere. The reaction mixture was quenched with satu-
rated NaHCO3 solution, extracted with CH2Cl2 (£2), and the
combined organic phase was washed with brine, dried over
Na2SO4 and concentrated. The residue was puri®ed by silica
gel column chromatography (33% ether in hexane) to afford