T. Sugimura et al. / Tetrahedron 63 (2007) 4027–4038
4037
(25.1 mg). The oil was purified by silica-gel column chro-
matography (elution with 30% ethyl acetate in hexane) to
give 24 as a yellow oil (17.4 mg, 86.5% yield). [a]2D0 +10.5
(c 0.6, CH2Cl2); IR (KCl, neat) 3454, 2930, 2714, 1713,
(d, J10,Me-10¼6.2 Hz, 1H, Me-10); 13C NMR (CDCl3,
150 MHz) d 101.31, 72.04, 65.70, 64.75, 41.37, 39.75,
39.46, 38.90, 35.57, 35.46, 24.18, 23.28, 22.08, 21.96,
17.25; HRMS (ESI) m/z (M+Na+) calcd for C15H28O3Na
279.1936, found 279.1915.
1
1463, 1380, 1258, 1126, 1050, 814, 730 cmꢀ1; H NMR
(CDCl3, 600 MHz) d 9.55 (d, J¼2.1 Hz, 1H), 3.71–3.65
(m, 2H), 2.83 (dt, J¼6.9, 2.1 Hz, 1H), 2.53–2.41 (m, 3H),
1.70 (dtd, J¼13.7, 6.9, 2.1 Hz, 1H), 1.62 (dtd, J¼13.7, 6.9,
2.7 Hz, 1H), 1.53 (dt, J¼15.1, 7.6 Hz, 2H), 1.42 (m, 1H),
1.31–1.22 (m, 3H), 1.13 (m, 1H), 1.06 (d, J¼6.9 Hz, 3H),
0.91 (d, J¼6.9 Hz, 3H), 0.88 (d, J¼6.9 Hz, 3H), 0.85 (m,
1H); 13C NMR (CDCl3, 150 MHz) d 214.70, 204.89,
63.78, 51.28, 43.91, 43.11, 37.94, 35.24, 28.52, 25.39,
22.28, 20.11, 14.12, 13.85; HRMS (ESI) m/z (M+Na+) calcd
for C14H22O3Na 265.17796, found 265.1726.
6.1.25. Synthesis of 29. To a solution of 28 (33.2 mg) in
THF/H2O (¼12:1, 6.5 mL) was added p-toluenesulfonic
acid (5 mg) at room temperature, and the mixture was stirred
for 20 h. The mixture was extracted with ether and the
extract was washed with water and then brine, dried over
sodium sulfate, concentrated, and purified by silica-gel col-
umn chromatography to give 17.4 mg of 29 as a colorless oil
(79% yield). [a]2D0 +96.5 (c 1.2, CH2Cl2); IR (KCl, neat)
3461, 2956, 1696, 1456, 1375, 1256, 1074, 852 cmꢀ1
;
1H NMR (CDCl3, 600 MHz) d 4.00 (dd, J2,3¼11.0 Hz,
JOH,2¼6.9 Hz, 1H, H-2), 3.55 (d, JOH,2¼6.9 Hz, 1H, OH),
2.58 (m, H-7), 1.76 (ddd, J¼14.4, 5.5, 2.1 Hz, 1H, H-4),
1.63 (ddd, J¼13.7, 4.8, 2.1 Hz, 1H, H-6), 1.47 (m, 1H, H-
3), 1.42 (m, 1H, H-5), 1.38 (m, 1H, H-60), 1.14 (m, 1H, H-
6.1.23. Synthesis of 26. To a solution of 14a (192 mg) and
triethylamine (0.25 mL, 2.4 equiv) in dry dichloromethane
(25 mL) was added methanesulfonyl chloride (66 mL,
1.2 equiv) at 0 ꢁC. Saturated sodium bicarbonate solution
was added after 25 min, and then the mixture was extracted
with dichloromethane (ꢃ3), washed with water (ꢃ2), and
dried over sodium sulfate. Concentration and purification
by column chromatography on silica-gel (elution with
50% ethyl acetate in hexane) gave 26 (217 mg) as a colorless
oil (73% yield). [a]2D0 +43.0 (c 0.56, CH2Cl2); IR (KCl, neat)
40), 1.13 (d, JMe-7,7¼7.6 Hz, 3H, Me-7), 1.10 (d, JMe-3,3
¼
6.9 Hz, 3H, Me-3), 0.95 (d, JMe-5,5¼6.9 Hz, 3H, Me-6);
13C NMR (CDCl3, 150 MHz) d 217.11, 78.29, 46.91,
45.20, 40.44, 38.78, 33.90, 24.64, 19.91, 9.65; HRMS
(ESI) m/z (M+Na+) calcd for C10H18O2Na 193.1204, found
193.1120.
3550, 2952, 1457, 1354, 1175, 1119, 1016, 935, 838 cmꢀ1
;
1H NMR (CDCl3, 600 MHz) d 4.54 (dd, J13,13 ¼9.6 Hz,
J13,12¼4.1 Hz, 1H, H-13), 4.06 (m, 1H, H-4), 4.01 (dd,
1H, H-130), 4.00 (m, 1H, H-2), 3.87 (d, J7,8¼6.2 Hz, 1H,
H-7), 2.97 (s, 3H, Me), 2.34 (s, 1H, OH-7), 2.30 (m, 1H,
H-12), 1.63 (m, 1H, H-11), 1.61 (m, 1H, H-8), 1.53 (m,
1H, H-10), 1.52 (m, 1H, H-110), 1.50 (m, 1H, H-3), 1.42
(m, 1H, H-9), 1.17 (m, 1H, H-90), 1.16 (d, J¼6.2, 3H, PD–
Me), 1.14 (d, J¼6.2 Hz, 3H, PD–Me), 1.09 (m, 1H, H-30),
6.1.26. Oxidative cleavage of 29 to give (D)-30. A solution
of 29 (12.8 mg) in anhydrous methanol (2 mL) and dry
benzene (2 mL) was added to lead tetraacetate (204 mg,
6 equiv) that was employed after washing with dry ether
(ꢃ2). After 10 min, small amount of ethylene glycol was
added followed by water. Extraction with ether (ꢃ4),
washed with water (ꢃ2), dried over sodium sulfate, and
then purification by silica-gel column chromatography (elu-
tion with 10% ethyl acetate in hexane) gave 11 mg of 30 as
a colorless oil (74% yield). [a]2D0 +19.4 (c 1.05, CH2Cl2); IR
0
1.08 (d, J8,Me-8¼6.9 Hz, 3H, Me-8), 0.88 (d, J10,Me-10
¼
6.2 Hz, 3H, Me-10); 13C NMR (CDCl3, 150 MHz)
d 100.80, 34.96, 71.59, 71.57, 66.23, 65.39, 40.36, 39.64,
39.27, 38.72, 37.08, 34.50, 24.02, 23.07, 21.94, 21.87;
HRMS (ESI) m/z (M+Na+) calcd for C18H30O6SNa
373.1661, found 373.1664.
1
(KCl, neat) 2969, 1736, 1461, 1380, 1173 cmꢀ1; H NMR
(CDCl3, 600 MHz) d 9.56 (d, J7,6¼2.1 Hz, 1H, H-7), 3.64
(s, 3H), 2.55 (m, 1H, H-6), 2.43 (m, 1H, H-6), 1.70 (ddd,
J¼13.7, 9.6, 4.8 Hz, 1H, H-3), 1.65 (ddd, 1H, H-5), 1.45
(m, 1H, H-4), 1.13 (d, J2,Me-2¼6.9 Hz, 3H, Me-2), 1.16
(m, 1H, H-50), 1.07 (m, 1H, H-30), 1.05 (d, J6,Me-6¼6.9 Hz,
3H, Me-6), 0.89 (d, J4,Me-4¼6.9 Hz, 3H, Me-4); 13C NMR
(CDCl3, 150 MHz) d 205.12, 177.17, 51.51, 43.89, 40.92,
38.06, 37.22, 28.49, 19.90, 18.17, 13.87; HRMS (ESI) m/z
(M+Na+) calcd for C11H20O4Na 239.1259, found 239.1260.
6.1.24. Synthesis of 28. To a solution of 26 (271 mg) in an-
hydrous ether (20 mL) was added lithium aluminum hydride
(65 mg) at 0 ꢁC, and the mixture was stirred for 24 h at the
same temperature. After addition of water, the mixture was
extracted with ether (ꢃ4), washed with water (ꢃ2), and
then brine. After drying over sodium sulfate, the mixture
was concentrated and purified by a short silica-gel column
(elution with 30% ethyl acetate in hexane) to give 185 mg
of 26 as a colorless oil (91% yield). [a]2D0 +50.2 (c 0.62,
MeOH); IR (KCl, neat) 3555, 2952, 1455, 1384, 1291,
6.1.27. Reduction of 30 by LiAlH4 to give 32. To a solution
of 30 (4.1 mg) in anhydrous ether (0.5 mL) was added lith-
ium aluminum hydride (ca. 15 mg, large excess) at 0 ꢁC.
After addition of water, the mixture was extracted with ether
(ꢃ3) and then dichloromethane (ꢃ2). Combined organic
layers were dried over sodium sulfate, concentrated, and
purified by silica-gel column chromatography (elution with
50% ethyl acetate in hexane) to give 2.3 mg of 32 as a color-
less oil (65%). [a]2D0 0.00 (c 0.09, CH2Cl2); IR (KCl, neat)
1176, 1114, 1013 cmꢀ1 1H NMR (CDCl3, 600 MHz)
;
d 4.03 (qdd, J¼17.9, 6.2, 2.8 Hz, 1H, H-4), 3.95 (qdd,
J¼17.9 Hz, J2,Me-2¼6.2 Hz, J¼2.8 Hz, 1H, H-2), 3.84 (d,
J7,8¼6.9 Hz, 1H, H-7), 2.51 (s, 1H, OH-7), 2.00 (qdd,
J12,Me-12¼6.9 Hz, J¼2.8 Hz, 1H, H-12), 1.63 (qddd,
J¼6.9, 2.1, 2.1, 2.1 Hz, 1H, H-8), 1.55 (m, 1H, H-10),
1.47 (m, 1H, H-12), 1.47 (m, 1H, H-3), 1.39 (m, 1H, H-
11), 1.28 (m, 1H, H-11), 1.14 (d, J4,Me-4¼6.2 Hz, 1H,
Me-4), 1.13 (d, J2,Me-2¼6.2 Hz, 1H, Me-2), 1.11 (m,
1H, H-11), 1.06 (m, 1H, H-3), 1.07 (d, J8,Me-8¼6.9 Hz,
1H, Me-8), 0.86 (d, J12,Me-12¼6.9 Hz, 1H, Me-12), 0.83
3333, 2918, 1461, 1378, 1039 cmꢀ1 1H NMR (CDCl3,
;
0
600 MHz) d 3.51 (dd, J1,1 ¼10.3 Hz, J1,2¼4.8 Hz, 2H, H-
1, 7), 3.37 (dd, J1,1 ¼10.3 Hz, J1,2¼6.9 Hz, 2H, H-10, 70),
0
1.71 (m, 2H, H-2, 6), 1.58 (m, 1H, H-4), 1.31 (ddd, 2H, H-
3, 5), 0.89 (m, 2H, H-30, 50), 0.91 (d, J2,Me-2¼6.9 Hz, 6H,
Me-2, 6), 0.89 (d, J4,Me-4¼6.9 Hz, 3H, Me-4); 13C NMR