ORDER
REPRINTS
HALOGENATED CYCLOHEXANE DERIVATIVES
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concentrated to a residue which was distilled at 137ꢁC to obtain the title
compound (5.9 g, 64%).
1H NMR (CDCl3): d 1.7 (s, 6H, 2 ꢀ CH3), 2.3–2.75 (m, 4H, H-3,30 and
H-6,60), 5.38 (br s, 2H, H-2 and H-4). (Found: C, 88.74; H, 11.2. calc. for
C10H12: C, 88.82; H, 11.18%).
1a,3-Dimethyl-1a,2,5,5a-tetrahydrobenzo[b]oxirene (3) and 1a,2a-
dimethyl perhydro oxireno[20,30:4,5]benzo[b]oxirene (4). To a mixture of
PCWP (1.3 g), 30% H2O2 (100 v) (2 mL) in CHCl3 (20 mL) was added
diene 2 (5 g, 46.3 mmol) and stirred for 2 h at room temperature. When
reaction was complete, the reaction mixture was diluted with water
(20 mL) and organic phase was separated. The aqueous phase was extracted
with chloroform (2 ꢀ 50 mL). Combined chloroform phases were dried
(Na2SO4) and concentrated to obtain a residue which was purified by
column chromatography (SiO2, 60–120 mesh) to elute first the monepoxide
3 [hexane : ethyl acetate: (25 : 1), 3.5 g, 65%] as a syrup.
1H NMR (CDCl3): d 1.4 (s, 3H, H-1, CH3), 1.65 (s, 3H, H-3, CH3),
2.10–2.70 (m, 4H, H-2,20 and H-5,50), 3.05 (br s, 1H, H-5a), 5.15 (brs, 2H,
H-4). Ms (m/z): 124. (Found: C, 77.21; H, 9.62. calc. for C8H12O: C, 77.38;
H, 9.74%) followed by diepoxide 4 [hexane : ethyl acetate: (9:1), 1.1 g, 17%]
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as a syrup. H NMR (CDCl3): d 1.25–1.28 (s, 6H, 2 ꢀ CH3), 2.8–2.9 (m,
2H, H-3,4). (Found: C, 68.42; H, 8.51. calc. for C8H12O2: C, 68.55;
H, 8.63%).
6-Hydroxy-4,6-dimethyl-3-cyclohexene-1-carbonitrile (5). To a solution
of epoxide 3 (3.2 g, 26.2 mmol) in N,N-dimethylformamide (5 mL) was
added sodium cyanide (3.8 g, 78.6 mmol) and the reaction mixture was stir-
red for 12 h at 90ꢁC. Progress of the reaction was monitored by TLC. When
the reaction was complete, the reaction mixture was cooled to room tem-
perature, diluted with water (50 mL) and extracted into diethyl ether
(2 ꢀ 50 mL). Combined etherial layers were washed with water, dried
(Na2SO4) and concentrated to obtained a residue which was purified by
column chromatography [(SiO2, 60–120 mesh; hexane; ethyl acetate: (8:2)]
to obtain the title compound 5 (2.4 g, 60%) as a syrup.
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IR: 2242 cmÀ1. H NMR (CDCl3): d 1.25 (s, 3H, 6-CH3), 1.65 (s, 3H,
4-CH3), 1.95–2.8 (m, 5H, H-2,20,1,5 and H-50), 4.9 (br s, 1H, OH), 5.25 (br s,
1H, H-3). Ms (m/z): 151. (Found: C, 71.28; H, 8.55; N, 9.19. calc. for
C9H13NO: C, 71.49; H, 8.67; N, 9.26%).
6-(2a,2a-Dibromovinyl)-1,3-dimethyl-3-cyclohexen-1-ol (7). To a solu-
tion of cyanohydrin 5 (3 g, 19.9 mmol) in dry CH2Cl2 (10 mL) was added
diisobutyl aluminium hydride solution in hexane (7.0 g, 24.8 mL, 49.7 mmol)
at À20ꢁC and stirred for 2 h. The reaction mixture was brought to room tem-
perature and stirred for 2 h. Progress of the reaction was monitored by TLC.
When reaction was complete, it was quenched by addition of methanol (3 mL)