Du et al.
1.60-1.63 (m, 1H), 2.09 (dd, 2H, J ) 6.8, 13.4 Hz), 2.43 (dd, 1H,
J ) 8.3, 15.8 Hz), 2.69 (dd, 1H, J ) 3.6, 15.8 Hz), 3.77 (dd, 1H,
J ) 3.9, 4.8 Hz), 3.86 (s, 3H), 4.16 (dd, 1H, J ) 2.6, 8.3 Hz),
4.36-4.39 (m, 2H), 4.62 (d, 1H, J ) 10.9 Hz), 4.65 (d, 1H, J )
11.1 Hz), 4.78 (d, 1H, J ) 11.1 Hz), 4.90-4.95 (m, 1H), 5.01 (d,
1H, J ) 10.2 Hz), 5.05 (d, 1H, J ) 18.4 Hz), 5.40 (d, 1H, J )
17.5 Hz), 5.43 (d, 1H, J ) 10.7 Hz), 5.80-5.86 (m, 1H), 6.01-
6.10 (m, 1H), 6.91 (d, 2H, J ) 8.4 Hz), 7.26-7.39 (m, 7H); 13C
NMR (CDCl3) δ -4.9, -4.7, 17.9, 19.8, 24.6, 25.8, 33.5, 35.3,
38.7, 55.2, 69.3, 69.7, 70.8, 72.9, 80.2, 82.2, 113.6, 114.7, 119.7,
127.2, 127.4, 128.2, 129.4, 130.8, 135.6, 138.4, 138.8, 159.0, 171.7.
Anal. Calcd for C35H52O6Si: C, 70.43; H, 8.78. Found: C, 70.72;
H, 8.91.
(S)-Hept-6-en-2-yl (3R,4S,5S)-5-Benzyloxy-3-hydroxy-4-(p-
methoxybenzyloxy)hept-6-enoate (24). To a solution of silyl ether
23 (358 mg, 0.6 mmol) in THF (10 mL) was added TBAF (1.2
mL of 1 M solution in THF, 1.2 mmol) at 0 °C. The mixture was
stirred under these conditions for 30 min, followed by an additional
4 h of stirring at room temperature. At the end of which time TLC
indicated the reaction complete. Then the reaction mixture was
concentrated under vacuum and the residue was subjected to column
chromatography (petroleum ether-EtOAc, 4:1) to furnish 24 (240
mg, 83%) as a colorless syrup: [R]25D -18 (c 1, CHCl3); 1H NMR
(CDCl3) δ 1.18 (d, 3H, J ) 6.2 Hz), 1.36-1.55 (m, 3H), 1.57-
1.60 (m, 1H), 2.04 (dd, 2H, J ) 7.0, 13.8 Hz), 2.43-2.50 (m, 2H),
3.09 (br s, 1H), 3.39-3.41 (m, 1H), 3.80 (s, 3H), 4.08 (t, 1H, J )
6.5 Hz), 4.32 (br s, 1H), 4.40 (d, 1H, J ) 11.4 Hz), 4.44 (d, 1H,
J ) 11.4 Hz), 4.60 (d, 1H, J ) 11.9 Hz), 4.63 (d, 1H, J ) 11.9
Hz), 4.89-4.96 (m, 2H), 4.99 (d, 1H, J ) 17.5 Hz), 5.39 (d, 1H,
J ) 16.6 Hz), 5.41 (d, 1H, J ) 10.8 Hz), 5.74-5.80 (m, 1H), 5.81-
5.91 (m, 1H), 6.85 (d, 2H, J ) 8.3 Hz), 7.20-7.34 (m, 7H); 13C
NMR (CDCl3) δ 19.9, 24.6, 33.4, 35.3, 38.9, 55.2, 68.1, 70.7, 71.0,
73.2, 80.4, 81.1, 113.7, 114.7, 119.5, 127.7, 127.9, 128.4, 129.8,
135.6, 137.7, 138.4, 159.3, 171.4. Anal. Calcd for C29H38O6: C,
72.17; H, 7.94. Found: C, 71.90; H, 8.05.
1.50-1.54 (m, 1H), 1.97 (dd, 2H, J ) 6.9, 13.4 Hz), 2.53 (br s,
1H), 2.87 (d, 2H, J ) 6.5 Hz), 3.83-3.89 (m, 2H), 4.27 (d, 1H, J
) 11.2 Hz), 4.52 (d, 1H, J ) 11.2 Hz), 4.87 (t, 1H, J ) 6.0 Hz),
4.92 (d, 1H, J ) 11.6 Hz), 4.95 (d, 1H, J ) 18.7 Hz), 5.36 (d, 1H,
J ) 17.4 Hz), 5.41 (d, 1H, J ) 10.3 Hz), 5.68-5.75 (m, 1H), 5.80
(t, 1H, J ) 6.3 Hz), 5.85-5.94 (m, 1H), 7.14-7.24 (m, 5H), 7.39
(t, 2H, J ) 7.4 Hz), 7.54 (t, 1H, J ) 7.0 Hz), 7.97 (d, 2H, J ) 7.9
Hz); 13C NMR (CDCl3) δ 19.8, 24.5, 33.4, 35.2, 36.8, 69.6, 70.7,
71.5, 73.8, 81.0, 114.7, 120.7, 127.6, 128.1, 128.2, 128.3, 129.7,
130.1, 132.9, 135.2, 137.6, 138.4, 165.5, 170.2. Anal. Calcd for
C28H34O6: C, 72.08; H, 7.35. Found: C, 72.42; H, 7.26.
(S)-Hept-6-en-2-yl (3R,5S)-3-Benzoyloxy-5-benzyloxy-4-oxo-
hept-6-enoate (5). To a solution of 26 (149 mg, 0.32 mmol) in
dry CH2Cl2 (15 mL) was added Dess-Martin periodinane (203 mg,
0.48 mmol) and the reaction mixture was stirred for 3 h at ambient
temperature. After extraction with saturated aqueous NaHCO3, the
organic layer was separated, dried over Na2SO4, and concentrated
under reduced pressure. The remaining residue was subjected to
column chromatography on silica gel (petroleum ether-EtOAc, 9:1)
to furnish compound 5 (121 mg, 82%) as a colorless syrup: [R]25
D
1
-17 (c 1, CHCl3), H NMR (CDCl3) δ 1.15 (d, 3H, J ) 6.2 Hz),
1.33-1.48 (m, 3H), 1.51-1.55 (m, 1H), 2.01 (dd, 2H, J ) 7.2,
14.1 Hz), 2.82 (dd, 1H, J ) 9.0, 16.2 Hz), 3.07 (dd, 1H, J ) 3.5,
16.1 Hz), 4.64 (d, 1H, J ) 5.8 Hz), 4.66 (d, 1H, J ) 10.8 Hz),
4.71 (d, 1H, J ) 11.6 Hz), 4.91-4.96 (m, 2H), 4.98 (d, 1H, J )
17.7 Hz), 5.42 (d, 1H, J ) 10.5 Hz), 5.49 (d, 1H, J ) 17.2 Hz),
5.65-5.77 (m, 1H), 5.84-5.92 (m, 1H), 6.08 (dd, 1H, J ) 3.4, 9.0
Hz), 7.28-7.37 (m, 5H), 7.43 (t, 2H, J ) 7.6 Hz), 7.57 (t, 1H, J
) 7.4 Hz), 8.01 (d, 2H, J ) 7.7 Hz); 13C NMR (CDCl3) δ 19.8,
24.6, 33.4, 35.2, 35.8, 71.9, 72.1, 73.3, 84.1, 114.8, 119.8, 127.9,
128.0, 128.4, 128.5, 129.1, 129.8, 132.3, 133.4, 137.0, 138.3, 165.5,
168.8, 203.1. Anal. Calcd for C28H32O6: C, 72.39; H, 6.94.
Found: C, 72.04; H, 7.05.
Lactone (4). Diene 5 (97 mg, 0.21 mmol) was dissolved in dry,
degassed CH2Cl2 (10 mL). This mixture was added dropwise within
1 h to a refluxing solution of ruthenium catalyst (54 mg, 0.06 mmol)
in dry, degassed CH2Cl2 (470 mL). The reaction mixture was stirred
under these conditions until the complete consumption of 5 (20-
24 h, TLC monitoring). After removing solvent in vacuo, the residue
was purified by silica gel column chromatography (petroleum
ether-EtOAc, 9:1) to yield 4 (66 mg, 72%) as a mixture of Z,E-
(S)-Hept-6-en-2-yl (3R,4S,5S)-3-Benzoyloxy-5-benzyloxy-4-(p-
methoxybenzyloxy)hept-6-enoate (25). To the solution of 24 (216
mg, 0.45 mmol) in pyridine (5 mL) were added benzoyl chloride
(0.06 mL, 0.67 mmol) and a catalytic amount of DMAP at 0 °C.
The mixture was stirred at room temperature for 3 h and coevapo-
rated with toluene under diminished pressure. Purification of the
residue on silica gel column chromatography (petroleum ether-
1
isomers (Z/E ) 1/2): selected H NMR (CDCl3) for E-isomer, δ
EtOAc, 8:1) afforded 25 (250 mg, 95%) as a colorless syrup: [R]25
1.18 (d, 3H, J ) 6.5 Hz), 1.40-1.49 (m, 1H), 1.56-1.76 (m, 3H),
1.84 (dd, 1H, J ) 11.2, 23.8 Hz), 2.30-2.33 (m, 1H), 2.97 (dd,
1H, J ) 5.0, 17.9 Hz), 3.47 (dd, 1H, J ) 3.3, 17.8 Hz), 4.57 (d,
1H, J ) 7.9 Hz), 4.68 (s, 2H), 4.95-4.97 (m, 1H), 5.41 (dd, 1H,
J ) 3.9, 15.7 Hz), 5.84-5.91 (m, 1H), 5.96 (t, 1H, J ) 3.8 Hz),
7.16-7.21 (m, 2H), 7.32-7.36 (m, 3H), 7.44 (t, 3H, J ) 7.2 Hz),
8.12 (d, 2H, J ) 7.9 Hz); for Z-isomer, δ 1.24 (d, 3H, J ) 6.3 Hz),
1.40-1.49 (m, 1H), 1.56-1.76 (m, 3H), 2.07-2.12 (m, 1H), 2.14-
2.19 (m, 1H), 2.83 (dd, 1H, J ) 9.8, 15.0 Hz), 3.06 (dd, 1H, J )
2.9, 15.0 Hz), 4.42 (d, 1H, J ) 11.6 Hz), 4.58 (d, 1H, J ) 11.8
Hz), 4.73 (d, 1H, J ) 8.3 Hz), 4.95-4.97 (m, 1H), 5.69 (t, 1H, J
) 8.6 Hz), 5.89-5.93 (m, 1H), 6.10 (dd, 1H, J ) 3.0, 9.8 Hz),
7.30-7.33 (m, 2H), 7.34-7.37 (m, 3H), 7.57 (t, 3H, J ) 7.8 Hz),
8.02 (d, 2H, J ) 7.9 Hz); selected 13C NMR (CDCl3) for E-isomer,
δ 18.3, 20.3, 29.7, 32.3, 35.3, 71.2, 72.4, 72.5, 84.2, 124.4, 127.5,
128.1, 128.4, 128.6, 129.6, 129.9, 130.0, 132.5, 133.3, 137.1, 165.7,
168.8, 200.9; ESI(+)-MS calcd for C26H28O6 436.19 [M], found
437.5 [M + H]+, 459.5 [M + Na]+. Anal. Calcd for C26H28O6 (E,Z
mixture): C, 71.54; H, 6.47. Found: C, 71.94; H, 6.39.
D
-17 (c 0.5, CHCl3); 1H NMR (CDCl3) δ 1.12 (d, 3H, J ) 6.1 Hz),
1.29-1.45 (m, 3H), 1.50-1.54 (m, 1H), 1.97 (dd, 2H, J ) 7.2,
14.0 Hz), 2.72-2.85 (m, 2H), 3.79 (s, 3H), 3.81 (dd, 1H, J ) 3.6,
5.8 Hz), 3.96 (t, 1H, J ) 6.7 Hz), 4.28 (d, 1H, J ) 11.4 Hz), 4.53
(d, 1H, J ) 10.9 Hz), 4.56 (d, 1H, J ) 10.3 Hz), 4.68 (d, 1H, J )
10.9 Hz), 4.86 (t, 1H, J ) 6.1 Hz), 4.91 (d, 1H, J ) 11.4 Hz), 4.95
(d, 1H, J ) 19.1 Hz), 5.35 (d, 1H, J ) 11.4 Hz), 5.36 (d, 1H, J )
16.1 Hz), 5.67-5.74 (m, 1H), 5.76-5.81 (m, 1H), 5.87-5.96 (m,
1H), 6.83 (d, 2H, J ) 8.3 Hz), 7.18-7.29 (m, 7H), 7.38 (t, 2H, J
) 7.6 Hz), 7.53 (t, 1H, J ) 7.1 Hz), 7.97 (d, 2H, J ) 7.7 Hz); 13
C
NMR (CDCl3) δ 19.7, 24.5, 33.4, 35.2, 36.3, 55.2, 70.2, 70.5, 71.3,
73.8, 80.2, 80.4, 113.6, 114.7, 119.7, 127.4, 127.9, 128.2, 129.7,
129.8, 130.1, 130.1, 132.8, 135.6, 138.0, 138.3, 159.2, 165.6, 170.1.
Anal. Calcd for C36H42O7: C, 73.70; H, 7.22. Found: C, 73.43; H,
7.13.
(S)-Hept-6-en-2-yl (3R,4S,5S)-3-Benzoyloxy-5-benzyloxy-4-
hydroxyhept-6-enoate (26). A solution of ester 25 (224 mg, 0.38
mmol) in CH2Cl2 (10 mL) at 0 °C was treated with DDQ (173 mg,
0.76 mmol) in the presence of water (1 mL). The mixture was stirred
at room temperature for 2 h and then quenched with saturated
aqueous NaHCO3. The aqueous layer was separated and extracted
with CH2Cl2 (2 × 20 mL). The combined organic extracts were
dried over anhydrous Na2SO4 and concentrated to dryness. Column
chromatography of the residue (petroleum ether-EtOAc, 5:1) gave
26 (160 mg, 90%) as a colorless syrup: [R]25D -17 (c 0.8, CHCl3);
1H NMR (CDCl3) δ 1.13 (d, 3H, J ) 6.1 Hz), 1.29-1.47 (m, 3H),
Sporiolide A (1). To a suspension of Pd/C (5% Pd, 15 mg) in
MeOH (8 mL) was added a solution of 4 (45 mg, 0.1 mmol) in
MeOH (4 mL). The mixture was allowed to stir at room temperature
for 24 h under 4 atm of H2 pressure, at the end of which of time
TLC indicated that the reaction was complete. The mixture was
filtered and concentrated in vacuo. The residue was subjected to
column chromatography on silica gel (petroleum ether-EtOAc, 7:1)
to furnish sporiolide A (1, 33 mg, 91%) as white amorphous solid:
8450 J. Org. Chem., Vol. 71, No. 22, 2006