T. Washio et al. / Tetrahedron 63 (2007) 12037–12046
12045
1.80–1.95 (m, 3H, C3–H, C4–H, and CH2CHHCH), 2.61–
2.76 (m, 2H, CH2CH2CH), 3.41–3.46 (m, 1H, C6–H), 3.80
(s, 3H, OCH3), 4.29 (dd, J¼2.1, 9.0 Hz, 1H, C2–H), 4.66
(br, 1H, OH), 6.71–6.75 (m, 2H, Ar), 6.86–6.90 (m, 2H,
Ar), 7.03–7.07 (m, 2H, Ar), 7.29–7.33 (m, 2H, Ar); 13C
NMR (100 MHz, CDCl3) d 23.9 (CH2), 30.6 (CH2), 31.1
(CH2), 33.1 (CH2), 38.1 (CH2), 55.1 (CH3), 76.9 (CH),
78.9 (CH), 113.4 (CH), 114.8 (CH), 126.9 (CH), 129.3
(CH), 134.4 (C), 135.5 (C), 153.2 (C), 158.4 (C). EI-
HRMS m/z calcd for C20H24O3 (M)+ 312.1725, found
312.1733. The synthetic material 1 was identical in all
respects with the reported spectral data for the natural
substance (IR, 1H NMR, 13C NMR, HRMS), including
optical rotation.
(83.7 mg, 96%) was obtained as a white solid: mp 181–
182 ꢁC [lit.,2a mp 183 ꢁC]; TLC Rf¼0.21 (2:1 hexane/
EtOAc); [a]2D2 ꢀ96.1 (c 1.02, MeOH) [lit.,2a [a]2D5 ꢀ95.1 (c
0.9, MeOH)]; IR (KBr) 3362, 1614 cmꢀ1
;
1H NMR
(400 MHz, acetone-d6) d 1.20–1.90 (m, 8H, C3–H, C4–H,
C5–H, and CH2CH2CH), 2.55–2.70 (m, 2H, CH2CH2CH),
3.37–3.44 (m, 1H, C6–H), 4.25 (dd, J¼2.3, 11.3 Hz, 1H,
C2–H), 6.71–6.80 (m, 4H, Ar), 6.99–7.03 (m, 2H, Ar),
7.19–7.22 (m, 2H, Ar), 8.03 (br, 1H, OH), 8.17 (br, 1H,
OH); 13C NMR (100 MHz, acetone-d6) d 24.7 (CH2), 31.4
(CH2), 32.0 (CH2), 34.6 (CH2), 39.4 (CH2), 77.6 (CH),
79.8 (CH), 115.5 (CH), 115.8 (CH), 127.8 (CH), 130.1
(CH), 133.9 (C), 135.9 (C), 156.1 (C), 157.1 (C). EI-
HRMS m/z calcd for C19H22O3 (M)+ 298.1569, found
298.1576. The synthetic material 2 was identical in all
respects with the reported spectral data for the natural sub-
4.6. Synthesis of (L)-de-O-methylcentrolobine
1
stance (IR, H NMR, 13C NMR, HRMS), including optical
4.6.1. (2S,6S)-2-(4-Hydroxyphenyl)-6-[2-(4-methane-
sulfonyloxyphenyl)ethyl]tetrahydropyran-4-one (11).
Following the procedure for the preparation of 10, starting
from 3d (240 mg, 0.50 mmol, >99% ee) and 10% Pd/C
(25 mg), 11 (190 mg, 97%) was obtained as a white solid:
mp 45.0–46.0 ꢁC; TLC Rf¼0.20 (1:1 hexane/EtOAc); [a]2D3
ꢀ69.9 (c 1.09, CHCl3); IR (KBr) 3421 (br), 1713, 1364,
rotation.
Acknowledgements
This research was supported, in part, by a Grant-in-Aid for
Scientific Research on Priority Areas ‘Advanced Molecular
Transformations of Carbon Resources’ from the Ministry of
Education, Culture, Sports, Science and Technology, Japan.
T.W. is grateful to JSPS for a graduate fellowship. We thank
Ms. S. Oka, M. Kiuchi, A. Maeda, and H. Matsumoto of the
Center for Instrumental Analysis at Hokkaido University for
mass measurements and elemental analysis.
1173, 1147 cmꢀ1 1H NMR (400 MHz, CDCl3) d 1.83–
;
1.92 (m, 1H, CH2CHHCH), 2.01–2.10 (m, 1H,
CH2CHHCH), 2.37–2.47 (m, 2H, COCH2), 2.53–2.63 (m,
2H, COCH2), 2.74–2.91 (m, 2H, CH2CH2CH), 3.13 (s, 3H,
SO2CH3), 3.69–3.75 (m, 1H, C6–H), 4.56 (dd, J¼3.2,
10.4 Hz, 1H, C2–H), 5.06 (br, 1H, OH), 6.84–6.87 (m, 2H,
Ar), 7.18–7.28 (m, 6H, Ar); 13C NMR (100 MHz, CDCl3)
d 30.9 (CH2), 37.2 (CH3), 37.6 (CH2), 47.5 (CH2), 49.2
(CH2), 75.9 (CH), 78.2 (CH), 115.4 (CH), 121.8 (CH),
127.1 (CH), 129.8 (CH), 132.3 (C), 140.7 (C), 147.2 (C),
155.6 (C), 207.7 (C]O); EI-HRMS m/z calcd for
C20H22O6S (M)+ 390.1137, found 390.1131. Anal. Calcd
for C20H22O6S: C, 61.52; H, 5.68; S, 8.21. Found: C,
61.54; H, 5.70; S, 8.48.
References and notes
1. (a) De Albuquerque, I. L.; Galeffi, C.; Casinovi, C. G.; Marini-
ꢀ
Bettolo, G. B. Gazz. Chim. Ital. 1964, 287–295; (b) Galeffi, C.;
Casinovi, C. G.; Marini-Bettolo, G. B. Gazz. Chim. Ital. 1965,
~
95–100; (c) Aragao Craveiro, A.; da Costa Prado, A.; Gottlieb,
O. R.; Welerson de Albuquerque, P. C. Phytochemistry 1970, 9,
ꢀ
^
1869–1875; (d) Alcantara, A. F.; de, C.; Souza, M. R.; Pilo-
Veloso, D. Fitoterapia 2000, 71, 613–615.
ꢁ
4.6.2. (2S,6R)-2-(4-Hydroxyphenyl)-6-[2-(4-methanesul-
fonyloxyphenyl)ethyl]tetrahydropyran (13). Following
the procedure for the preparation of 12, starting from 11
(160 mg, 0.40 mmol) and TsNHNH2 (74 mg, 0.40 mmol),
TsOH$H2O (23 mg, 0.12 mmol) and NaBH3CN (100 mg,
1.6 mmol), 13 (112 mg, 75%) was obtained as a white solid:
mp 126–127 ꢁC; TLC Rf¼0.28 (3:2 hexane/EtOAc); [a]2D2
ꢀ57.5 (c 1.00, CHCl3); IR (KBr) 3356 (br), 1352, 1175,
2. (a) Jurd, L.; Wong, R. Y. Aust. J. Chem. 1984, 37, 1127–1133;
(b) Araujo, C. A. C.; Alegrio, L. V.; Leon, L. L. Phytochemistry
1998, 49, 751–754.
3. (a) Prasain, J. K.; Li, J.-X.; Tezuka, Y.; Tanaka, K.; Basnet, P.;
Dong, H.; Namba, T.; Kadota, S. J. Nat. Prod. 1998, 61, 212–
216; (b) Gewali, M. B.; Tezuka, Y.; Banskota, A. H.; Ali, M. S.;
Saiki, I.; Dong, H.; Kadota, S. Org. Lett. 1999, 1, 1733–1736;
(c) Tezuka, Y.; Ali, M. S.; Banskota, A. H.; Kadota, S.
Tetrahedron Lett. 2000, 41, 5903–5907; (d) Tezuka, Y.;
Gewali, M. B.; Ali, M. S.; Banskota, A. H.; Kadota, S.
J. Nat. Prod. 2001, 64, 208–213; (e) Ali, M. S.; Tezuka, Y.;
Banskota, A. H.; Kadota, S. J. Nat. Prod. 2001, 64, 491–496;
(f) Ali, M. S.; Banskota, A. H.; Tezuka, Y.; Saiki, I.; Kadota,
S. Biol. Pharm. Bull. 2001, 24, 525–528.
1
1151 cmꢀ1; H NMR (400 MHz, CDCl3) d 1.25–1.95 (m,
8H, C3–H, C4–H, C5–H, and CH2CH2CH), 2.69–2.85
(m, 2H, CH2CH2CH), 3.12 (s, 3H, SO2CH3), 3.41–3.48
(m, 1H, C6–H), 4.28 (dd, J¼2.3, 10.8 Hz, 1H, C2–H),
4.78 (br, 1H, OH), 6.78–6.82 (m, 2H, Ar), 7.16–7.26 (m,
6H, Ar); 13C NMR (100 MHz, acetone-d6) d 25.1 (CH2),
32.1 (CH2), 32.4 (CH2), 34.9 (CH2), 37.7 (CH3), 39.3
(CH2), 77.9 (CH), 80.2 (CH), 115.9 (CH), 123.1 (CH),
128.1 (CH), 131.0 (CH), 136.1 (C), 143.0 (C), 148.8 (C),
157.4 (C); EI-HRMS m/z calcd for C20H24O5S (M)+
376.1344, found 376.1336. Anal. Calcd for C20H24O5S: C,
63.81; H, 6.43; S, 8.52. Found: C, 63.41; H, 6.41; S, 8.65.
4. Yin, J.; Kouda, K.; Tezuka, Y.; Tran, Q. L.; Miyahara, T.; Chen,
Y.; Kadota, S. Planta Med. 2004, 70, 54–58.
5. For total syntheses and structure revisions of calyxins F, G, L,
and M and epicalyxins G and M, see: (a) Tian, X.; Jaber, J. J.;
Rychnovsky, S. D. J. Org. Chem. 2006, 71, 3176–3183; For to-
tal syntheses of blepharocalyxin D, see: (b) Ko, H. M.; Lee,
D. G.; Kim, M. A.; Kim, H. J.; Park, J.; Lah, M. S.; Lee, E.
Org. Lett. 2007, 9, 141–144; (c) Ko, H. M.; Lee, D. G.; Kim,
4.6.3. (L)-De-O-methylcentrolobine (2). Following the
procedure for the preparation of 1, starting from 13
(110 mg, 0.29 mmol) and K2CO3 (400 mg, 2.9 mmol), 2