Syn the sis of Elvirol Methyl Ether
J. Chin. Chem. Soc., Vol. 48, No. 5, 2001 881
tographytogive 11 (0.06 g, 90%). IR (film) 1729 cm-1; 1H
NMR 1.16 (3H, d,J = 5.1 Hz), 1.83-1.91 (2H, m), 2.14-2.22
(2H, m), 2.26 (3H, s), 3.14-3.17 (1H, m), 3.58 (3H, s), 3.76
(3H, s), 6.68-6.91 (3H, m);13C NMR 20.8 (q), 20.9 (q), 31.5
(d), 32.3 (t), 51.3 (q), 55.4 (q), 110.4 (d), 127.2 (d), 127.6 (d),
129.6 (s), 134.0 (s), 155.0 (s), 174.1 (s); HRMS (m/z)
236.1406 (236.1413 calcd. for C 17H20O3).
(2H, m), 1.85 (3H, s), 2.04 (2H, m), 2.42 (3H, s), 3.28 (1H,
m), 3.88 (3H, s), 5.24 (1H, t, J = 6.9 Hz), 6.80-7.43 (3H, m);
13C NMR 17.6 (q), 20.7 (q), 21.2 (q), 25.8 (q), 26.4 (t), 31.5
(d), 37.2 (t), 55.3 (q), 110.4 (d), 125.1 (d), 126.7 (d), 127.5
(d), 129.4 (s), 130.8 (s), 135.5 (s), 157.5 (s); HRMS (m/z)
232.1820 (232.1828 calcd. for C16H24O).
4-(2-Methoxy-5-methylphenyl)pentanal (12)
ACKNOWLEDGMENT
To a stirred so lu tion of es ter11 (0.07 g, 0.3 mmol) in
dry to lu ene (2 mL) at -78 was added diisobutylaluminum
hy dride (1 M in hex ane, 0.26 mL, 0.39 mmol). The re ac tion
was maintained at -70 for 4 h, quenched with saturated
NH4Clsolution, warmedtoroomtemperatureandseparated
intolayersafteraddingdichloromethane. Thecrudeproduct
was treated with pyridinium chlorochromate (0.1 g, 0.45
mmol) to reoxidize the overreduced ma te rial for 0.5 h. Sol-
vent re moval and chro ma tog ra phy gave the al de hyde 12
(0.056 g, 91.7%). IR (film) 1708 cm-1; 1H NMR 1.15 (3H,
d, J = 7.5 Hz), 1.82-1.94 (2H, m), 2.20-2.36 (2H, m), 2.27
(3H, s), 3.14-3.21 (1H, m), 3.76 (3H, s), 6.69-6.93 (3H, m),
9.66 (1H, t); 13C NMR 20.7 (q), 20.9 (q), 29.6 (t), 31.4 (d),
42.2 (t), 55.4 (q), 110.5 (d), 127.3 (d), 127.6 (d), 129.7 (s),
133.8 (s), 154.9 (s), 202.1 (d); HRMS (m/z) 206.1309
(206.1307 calcd. for C13H18O2).
We thank the Na tional Sci ence Coun cil, Re pub lic of
China,forfinancialsupport.
Received May 10, 2001.
Key Words
Sesquiterpenes; Ozonolysis; Wittig reaction;
Elvirol methyl ether.
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2-(1,5-Dimethyl-4-hexenyl)-4-methylphenyl Methyl Ether
{Elvirol methyl ether} (1b)
n-Butyllithium (1.6 M in hex ane, 0.12 mL, 0.2 mmol)
was added to a stirred suspension of isopropyltriphenyl-
phosphonium io dide (80 mg, 0.2 mmol) in tetrahydrofuran (2
mL) at 0 .After10min,asolutionofthealdehyde12 (20 mg,
0.1 mmol) in dry tetrahydrofuran (1 mL) was introduced
dropwise via a sy ringe. Af ter 2 h the re ac tion mix ture was
quenched with meth a nol (1 mL) and chromatographed over
sil ica gel to give 1b (16.1 mg, 71.6%). IR (film) 1610 cm-1;
1H NMR 1.33 (3H, d, J = 7.2 Hz), 1.59 (3H, s), 1.68-1.76
9. Schreiber, S. L.; Claus, R. E.; Rea gan, J. Tetrahedron
Lett. 1982, 23, 3867.