6490
R. E. Patre et al. / Tetrahedron Letters 50 (2009) 6488–6490
75 MHz) d 18.19, 18.23, 25.70, 25.75, 65.14, 65.43, 99.65, 106.43, 118.81,
118.90, 119.23, 130.18, 138.81, 139.01, 163.04, 165.33, 188.39. HRMS m/z
[M+Na]+ 297.1460 (calcd for C17H22O3Na, 297.1467).
using appropriate Wittig reagent on this double Claisen–Cope rear-
rangements and the possibility of cascade Wittig multiple Claisen–
Cope rearrangements will be undertaken.
(b) Cascade Wittig reaction, double Claisen, Cope rearrangements of 2,4-
diprenyloxybenzaldehyde 4.
A
solution of 2,4-diprenyloxybenzaldehyde
4
(0.20 g, 0.73 mmol) and phosphorane
5
(0.38 g, 1.1 mmol) and diphenyl
Acknowledgments
ether (10 mL) was refluxed for 4 h. The reaction mixture was loaded over silica
gel column. Using hexanes, diphenyl ether was removed, followed by elution
with ethyl acetate and hexanes (1:1) separated triphenylphosphine oxide from
the mixture of coumarins. The mixture of coumarins was then further purified
by flash chromatography using ethyl acetate and hexanes (1:9) as eluent. First
fraction gave 3-(3-methylbut-2-enyl)-7-(3-methylbut-2-enyloxy) coumarin
(9), second fraction gave 8,9,9-trimethyl-6-(3-methylbut-2-enyl)-8,9-
dihydro-2H-furo[2,3-h]chromen-2-one (10), third fraction gave 6,8-
diprenylumbelliferone (3), fourth fraction gave balsamiferone (2), fifth
fraction gave gravelliferone (1), and the last fraction gave demethylsuberosin
(11).
We thank IISc, Bangalore, for HRMS and CSIR, New Delhi, for
financial support.
References and notes
1. (a) Posner, G. H. Chem. Rev. 1986, I, 831; (b) Jasperse, C. P.; Curran, D. P.; Fevig,
T. L. Chem. Rev. 1991, 91, 1237; (c) Nicolaou, K. C.; Edmonds, D. J.; Bulger, P. G.
Angew. Chem., Int. Ed. 2006, 45, 7134; (d) Pelliser, H. Tetrahedron 2006, 4, 2076;
(e) Kirsch, S. F. Synthesis 2008, 20, 3183.
2. (a) Tietze, L. F. Chem. Rev. 1996, 96, 115; (b) Tietze, L. F.; Beifuss, U. Angew.
Chem., Int. Ed. Engl. 1993, 32, 131; (c) Tietze, L. F.; Lieb, M. Curr. Opin. Chem. Biol.
1998, 2, 363; (d) Tietze, L. F.; Modi, A. Med. Res. Rev. 2000, 20, 304; (e) Tietze, L.
F.; Brasche, G.; Gericke, G. Domino Reactions in Organic Synthesis; Wiley-VCH:
Weinheim, 2006.
3. (a) Parsons, P. J.; Penkett, C. S.; Shell, A. J. Chem. Rev. 1996, 96, 195; (b) Ho, T. L.
Tandem Reactions in Organic Synthesis; Wiley Interscience: New York, 1997;
(c) Taylor, R. J. K.; Reid, M. F.; Raw, R. A. Acc. Chem. Res. 2005, 48, 851.
4. (a) Schobert, R.; Gordon, G. J. Curr. Org. Chem. 2002, 6, 1181; (b) Taylor, R. J. K.;
Quesada, E. Synthesis 2005, 19, 3193.
5. (a) Majik, M. S.; Parameswaran, P. S.; Tilve, S. G. J. Org. Chem. 2009, 74, 3591; (b)
Patre, R. E.; Gawas, S.; Parameswaran, P. S.; Tilve, S. G. Tetrahedron Lett. 2007,
48, 3517; (c) Desai, V. G.; Manekar-Tilve, A. S.; Tilve, S. G. Synth. Commun. 1996,
29, 3017; (d) Shet, J. B.; Desai, V. G.; Tilve, S. G. Synthesis 2004, 11, 1859; (e)
Desai, V. G.; Mali, R. S.; Tilve, S. G. J. Chem. Res. (M), 2000, 8, 0150.
6. O’Kennedy, R.; Thornes, R. D.. Coumarins: Biology, Applications and Mode of
Action; Wiley & Sons: Chichester, 1997.
7. Murray, R. D. In Natural Coumarin: Occurrence, Chemistry and Biochemistry; John
Wiley & Sons, 1982.
8. Reisch, J.; Szendrei, K.; Minker, K. E.; Novak, I. Experientia 1968, 24, 992.
9. Burke, B. A.; Parkins, H. Phytochemistry 1979, 18, 1073.
10. (a) Prakash, D.; Lakshmi, V.; Raj, K.; Kapil, R. S. Fitoterapia 1989, 60, 347; (b) Ito,
C.; Itoigawa, M.; Ju-ichi, M.; Sakamoto, N.; Tokuda, H.; Nishino, H.; Furukawa,
H. Plant Med. 2005, 71, 84.
11. (a) Massanet, G. M.; Pando, E.; Rodriguez-Luis, F.; Salva, J. Heterocycles 1987, 26,
154; (b) Massanet, G. M.; Pando, E.; Rodriguez-Luis, F.; Salva, J. Heterocycles
1988, 27, 775; (c) Cairns, N.; Harwood, L. M.; Astle, D. P. J. Chem. Soc., Perkin
Trans. 1 1994, 3101.
3-(3-Methylbut-2-enyl)-7-(3-methylbut-2-enyloxy) coumarin (9): Yield: 5.4 mg
(2.5%); gummy mass; IR (KBr) 1725 (CO) cmꢁ1 1H NMR (300 MHz, CDCl3) d
;
1.70 (3H, s), 1.78 (3H, s), 1.82 (6H, s), 3.24 (2H, d, J = 6.9 Hz), 4.57 (2H, d,
J = 6.9 Hz), 5.32 (1 H, m), 5.49 (1H, m), 6.85 (2H, m), 7.33 (1H, d, J = 9.0 Hz), 7.40
(1H, s); 13C NMR (75 MHz, CDCl3) d 17.82, 18.27, 25.80, 28.67, 65.33, 100.00,
101.20, 112.93, 113.19, 118.83, 119.48, 120.00, 125.22, 128.00, 135.36, 138.14,
139.00, 162.90; HRMS m/z [M+H]+ 299.1637 (calcd for C19H23O3, 299.1647).
8,9,9-Trimethyl-6-(3-methylbut-2-enyl)-8,9-dihydro-2H-furo[2,3-h]chromen-2-one
(10): Yield: 33 mg (15%); white solid; mp 136–137 °C: Lit.11 136–139 °C; IR
(KBr) 1725 (CO) cmꢁ1 1H NMR (300 MHz, CDCl3) d 1.42 (3H, d, J = 6.6 Hz), 1.57
;
(3H, s), 1.58 (3H, s), 1.71 (3H, s), 1.77 (3H, s), 3.29 (2H, d, J = 7.2 Hz), 5.29 (1H,
m), 4.50 (1H, q, J = 6.6 Hz), 6.17 (1H, d, J = 9.3 Hz), 7.00 (1H, s), 7.60 (1H, d,
J = 9.3 Hz); 13C NMR (75 MHz, CDCl3): d 14.16, 17.71, 20.97, 25.33, 25.68, 27.16,
44.38, 111.66, 113.09, 120.99, 121.25, 121.80, 127.33, 133.58, 144.27, 150.04,
160.32; HRMS m/z [M+H]+ 299.1645 (calcd for C19H23O3, 299.1647).
6,8-Diprenylumbelliferone (3): Yield: 33 mg (15%); white solid; mp 134–136 °C;
IR (KBr) 3420 (OH) and 1725 (CO) cmꢁ1 1H NMR (300 MHz, CDCl3) d 1.78 (6H,
;
s), 1.81 (3H, s), 1.88 (3H, s), 3.37 (2H, d, J = 6.9 Hz), 3.63 (2 H, d, J = 6.9 Hz), 5.30
(2H, m), 6.11 (1H, s), 6.24 (1H, d, J = 9.3 Hz), 7.09 (1 H, s), 7.61 (1H, d,
J = 9.3 Hz); 13C NMR (75 MHz, CDCl3): d 17.87, 22.26, 25.81, 28.88, 112.32,
112.54, 114.49, 120.46, 121.06, 124.81, 125.92, 135.16, 135.89, 144.02, 151.06,
156.57, 161.55. HRMS m/z [M+Na]+ 321.1457 (calcd for C19H22O3Na, 321.1467).
Balsamiferone (2): Yield: 11 mg, (5%); white solid; mp 135–136 °C: Lit11 134–
136 °C; IR (KBr) 3420 (OH) and 1725 (CO) cmꢁ1 1H NMR (300 MHz, CDCl3) d
;
1.71 (3H, s), 1.76 (3H, s), d 1.80 (3H, s), 1.81 (3H, s), 3.23 (2H, d, J = 6.9 Hz), 3.39
(2H, d, J = 6.9 Hz), 5.30 (2H, m), 6.99 (1H, s), 7.16 (1H, s), 7.41 (1H, s); 13C NMR
(75 MHz, CDCl3); d 17.62, 25.82, 28.46, 102.75, 112.97, 119.53, 121.00, 124.55,
125.39, 127.63, 134.70, 135.33, 139.00, 155.82, 157.28, 163.22; HRMS m/z
[M+Na]+ 321.1459 (calcd for C19H22O3Na, 321.1467).
Gravelliferone (1): Yield: 22 mg (10%); white solid; mp 165–166 °C: Lit11 mp
12. Nicolaou, K. C.; Lister, T.; Denton, R. M.; Gelin, C. F. Angew. Chem., Int. Ed. 2007,
46, 7501.
166–167 °C; IR (KBr) 3480 (OH) and 1725 (CO) cmꢁ1 1H NMR (300 MHz,
;
CDCl3) d 1.45 (6H, s), 1.78 (3H, s), 1.81 (3H, s), 3.39 (2H, d, J = 7.2 Hz), 5.08 (2H,
m), 5.32 (1H, t), 6.18 (1H, dd, J = 10.8 and 16.8 Hz), 6.54 (1H, brs,), 6.94 (1H, s),
7.19 (1H, s), 7.54 (1H, s). HRMS m/z [M+Na]+ 321.1461 (calcd for C19H22O3Na,
321.1467).
13. (a) Procedure for the synthesis of 2,4-diprenyloxybenzaldehyde (4):To the mixture
of resorcylaldehyde (2.00 g, 14.50 mmol) and potassium carbonate (5.00 g,
36.23 mmol) in acetone (40 mL), prenylbromide (5.20 g, 36.23 mmol) was
added slowly in portions. The reaction mixture was refluxed for 12 h. It was
then cooled, filtered, and acetone was removed under vacuum. To this, water
(20 mL) was added and extracted with diethyl ether (3 ꢀ 20 mL). The
combined organic layer was washed with 2 N sodium hydroxide (2 ꢀ 15 mL)
and then with water (2 ꢀ 15 mL). The organic layer was dried over anhydrous
sodium sulfate. Evaporation of the solvent under reduced pressure gave a
viscous liquid, which was purified over silica gel column chromatography
(EtOAc/hexanes = 1:99) to afford 3.30 g (82.50%) of 2,4-diprenyloxy-
Demethylsuberosin (11): Yield: 33 mg (20%); white solid; mp 134–136 °C: Lit11
133–135 °C; IR (KBr) 3420 (OH) and 1725 (CO) cmꢁ1 1H NMR (300 MHz,
;
CDCl3) d 1.75 (3H, s), 1.79 (3H, s), 3.38 (2H, d, J = 7.2 Hz), 5.31 (1H, t, J = 7.2 Hz),
6.24 (1H, d, J = 9.3 Hz), 7.00 (1H, s), 7.21 (1H, s), 7.67 (1H, d, J = 9.3 Hz); 13C
NMR (75 MHz, CDCl3); d 17.83, 25.80, 28.03, 102.77, 111.98, 112.00, 121.25,
126.39, 128.14, 134.27, 144.72, 154.02, 158.88, 162.95. HRMS m/z [M+H]+
231.1022 (calcd for C14H15O3, 231.1021).
benzaldehyde 4 as a yellow oil; IR (KBr) 1675 (CO) cmꢁ1
;
1H NMR (300 MHz,
14. (a) Sharma, R. B.; Swarrop, D.; Kapil, R. S. Indian J. Chem. 1983, 22B, 408; (b)
Sharma, R. B.; Swarrop, D.; Kapil, R. S. Indian J. Chem. 1982, 22B, 105; (c) Mali, R.
S.; Sandhu, P. K.; Manekar-Tilve, A. J. Chem. Soc., Chem. Commun. 1994, 251.
CDCl3) d 1.77 (6H, s), 1.81 (6H, s), 4.59 (4H, m), 5.50 (2H, m), 6.48 (1H, s), 6.55
(1H, d, J = 8.7 Hz), 7.81 (1H, d, J = 8.7 Hz), 10.30 (1H, s); 13C NMR (CDCl3,