over SiO (petroleum ether:EtOAc, 9:1) isolated nopinone (3) and 4-isopropylphenol (4). Yield of 3, 3.5 g (70%), light-
2
yellow oil; 4, 0.8 g (15%), colorless crystals, mp 62°C.
13
The PMR and C NMR spectra of 3 were analogous to those reported [7]; for 4, [8].
b. Compound 1 (5 g, 37.7 mmol) was ozonolyzed analogously to that described in a. The reaction mixture was added
dropwise to a solution of FeCl ·6H O (81.5 mL, 1 M) in MeOH at room temperature and worked up analogously to that
3
2
20
described above to afford 3 and 5. Yield of 3, 1.5 g (30%); of 5, 2.9 g (45%), colorless oil, [ꢀ] +73.5° (c 0.83, CH Cl ).
D
2
2
–1
For 5, IR spectrum (ꢅ, cm ): 735 (C–Cl), 1200, 1458, 1728 (C=O), 2872, 2953.
2
PMR spectrum (CDCl , , ppm, J/Hz): 0.8, 1.32 (6H, s, gem-CH ), 2.0 (1H, d, J = 10.9, H -7), 2.25 (1H, ddd,
3
3
e
3
2
3
2
3
J = 6.5, 5.3, 2.0, H-5), 2.30 (1H, ddd, J = 13.3, J = 8.9, 2.0, H -4), 2.65 (1H, ddd, J = 10.9, J = 5.6, 6.5, H -7), 2.70 (1H,
ddd, J = 13.3, J = 5.3, 1.7, H -4), 2.75 (1H, d, J = 5.6, H-1), 4.22 (1H, dd, J = 8.9, 1.7, H-3).
a
a
2
3
e
13
C NMR spectrum (CDCl , , ppm): 22.64 (CH ), 25.50 (C-7), 25.81 (CH ), 34.20 (C-4), 40.47 (C-5), 42.02 (C-6),
3
3
3
52.47 (C-3), 57.99 (C-1), 206.53 (C-2). C H ClO.
9
13
c. Compound 1 (2 g, 14.8 mmol) in anhydrous MeOH (50 mL) was ozonolyzed analogously to that in the preceding
experiment. The reaction mixture was treated with a solution of Fe(NO ) ·9H O (32 mL, 1 M) in MeOH at room temperature
3 3
2
and stirred for 1 h. The MeOH was distilled off. The solid was extracted with petroleum ether. The extract was dried over
Na SO . The solvent was evaporated. Yield of 3, 1.9 g (97%).
2
4
Ozonolysis of 2. An O /O mixture was bubbled through a solution of 2 (3 g, 22.2 mmol, ee 51%) in anhydrous
3
2
MeOH (72 mL) until 22.2 mmol of O was absorbed. The resulting methoxyhydroperoxide was treated dropwise with a
3
solution of FeCl ·6H O (48 mL, 1 M) in MeOH at room temperature and stirred for 1 h. The MeOH was evaporated at reduced
3
2
pressure. The solid was treated with petroleum ether, washed with H O, and dried over Na SO to afford crude product
2
2
4
20
(1.8 g) from which chromatography over SiO (petroleum ether:EtOAc, 9:1) isolated 6, yield 1.6 g (53%), [ꢀ] +30.9°
2
D
(c 0.86, CHCl ) and 7, yield 1 g (30%),+20.9° (c 1.49, CH Cl ). The spectral properties of 6 were identical to those published
3
2
2
[9]; of 7, [6].
ACKNOWLEDGMENT
The work was supported financially by the Ministry of Education and Science (State Contract No. 14.740.11.0367).
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