+
1
C
5.8 (CH
3
); m/z (ES+) 169 ([M + H] , 100%); found 186.1485,
(± )-syn-2-(2-Methylprop-1-enyl)-7-oxabicyclo[4.1.0]heptan-2-ol
and (± )-anti-2-(2-methylprop-1-enyl)-7-oxabicyclo[4.1.0]heptan-
+
10
H
20NO
2
(M + NH
4
) requires 186.1489.
2-ol (17)
(
(
± )-1-Methyl-2-((E)-prop-1-enyl)-6-oxabicyclo[3.1.0]hexan-2-ol
7) and (± )-1-methyl-2-((Z)-prop-1-enyl)-6-oxabicyclo[3.1.0]-
Flash chromatography using 10% ethyl acetate in petroleum ether
as eluent gave the less polar product (112 mg, 15%) as a colourless
hexan-2-ol (8)
oil, R
polar product (164 mg, 22%) as a colourless oil, R
acetate in petroleum ether). Less polar product: mmax/cm 3458
br (OH), 2937 (C–H), 1441; d (300 MHz; CDCl ) 5.37 (1H, s,
CH=C(CH
), 3.40 (1H, m, CH CHO), 3.24 (1H, d, J = 3.6 Hz,
CHOCHCH ), 2.46 (1H, br s, OH), 2.05–1.97 (1H, m, CH), 1.85
(3H, s, CH ), 1.75–1.61 (4H, m, CH and CH), 1.48–1.33 (4H, m,
(75 MHz; CDCl ) 136.2 (C), 128.4 (CH), 69.9 (C),
8.8, 56.1 (CH), 35.8 (CH ), 26.8 (CH ), 23.4 (CH ), 19.6 (CH ),
f
0.26 (10% ethyl acetate in petroleum ether), and the more
f
0.14 (10% ethyl
The crude product (∼0.8 : 1, Z/E) was purified by column
chromatography on silica using 10% ethyl acetate in petroleum
ether as eluent to give the (E)-tertiary alcohol 7 (134 mg, 43%)
as a colourless oil, R
and the (Z)-tertiary alcohol 8 (100 mg, 32%) as a colourless oil,
−
1
H
3
3
)
2
2
f
0.23 (10% ethyl acetate in petroleum ether),
2
−
1
3
3
R
f
0.33 (10% ethyl acetate in petroleum ether). 7: mmax/cm 3447
br (OH), 2935 (C–H); d (300 MHz; CDCl ) 5.84–5.73 (1H, dq,
J = 6.5 and 15.3 Hz, CH=CHCH
), 5.47 (1H, d, J = 15.3 Hz,
CH=CHCH
), 3.36 (1H, s, C(5)H), 2.06–2.00 (1H, m, CH), 1.91–
.88 (1H, m, CH), 1.81–1.52 (5H, m, 2 × CH and CH ), 1.35 (3H, s,
CH ); d (75 MHz; CDCl ) 131.7, 124.3 (CH), 80.6, 67.3 (C), 63.1
CH), 34.8, 25.3 (CH ), 17.9, 12.3 (CH
); m/z (ES+) 137 ([M −
OH] , 100%); found 177.0889, C Na requires 177.0886. 8:
(300 MHz; CDCl ) 5.64–
.53 (1H, dq, J = 7.1 and 11.7 Hz, CH=CHCH
), 5.30 (1H, d, J =
1.7 Hz, CH=CHCH
), 3.37 (1H, s, C(5)H), 2.03–1.52 (7H, m,
× CH and CH ), 1.42 (3H, s, CH ); d (75 MHz; CDCl ) 130.2,
27.7 (CH), 82.0, 67.8 (C), 63.6 (CH), 36.7, 25.3 (CH ), 14.8, 12.2
4
5
1
1
× CH); d
C
3
H
3
2
3
+
2
3
+
3
5.9 (CH
00); found 186.1498, C10
2
); m/z (ES+) 169 ([M + H] , 55%), 151 ([M − OH] ,
3
+
H
20NO
2
(M + NH
4
) requires 186.1489.
1
3
−
1
More polar product: mmax/cm 3437 br (OH), 2936 (C–H), 1446;
(300 MHz; CDCl ), 3.27 (1H, m,
CHO), 3.12 (1H, d, J = 3.9 Hz, CHOCHCH ), 1.93 (3H, s,
), 1.88–1.84 (2H, m, CH and OH), 1.75 (3H, s, CH ), 1.71–
3
C
3
d
H
3
) 5.43 (1H, s, CH=C(CH
)
3 2
(
2
3
+
CH
CH
2
3
2
9
H
14
O
2
−
1
3
m
max/cm 3465 br (OH), 2933 (C–H); d
H
3
1
.63 (2H, m, 2 × CH), 1.54–1.43 (2H, m, 2 × CH), 1.32–1.25 (1H,
m, CH); d (75 MHz; CDCl ) 137.2 (C), 129.1 (CH), 70.2 (C),
8.2, 53.9 (CH), 34.5 (CH ), 27.1 (CH ), 23.1 (CH ), 19.3 (CH ),
5.5 (CH
); m/z (ES+) 169 ([M + H] , 10%), 151 ([M − OH] ,
requires 186.1489.
5
1
4
1
(
7
3
C
3
3
5
1
2
3
+
2
3
+
3
3
C
3
2
2
+
+
100); found 186.1492, C10
H
20NO
2
CH
3
); m/z (ES+) 137 ([M − OH] , 100%), 121 ([M − OH − O] ,
5); found 177.0888, C Na requires 177.0886.
9
H
14
O
2
3
-(2-Methylprop-1-enyl)cyclohex-2-enone (19)
(
± )-(2S,3R)-3-Hydroxy-2-methyl-2-((E)-prop-1-enyl)cyclopenta-
From the more polar isomer: flash chromatography using 20%
diethyl ether in petroleum ether as eluent gave the title compound
none (14)
(
44 mg, 64%) as a colourless oil, R 0.26 (10% ethyl acetate
f
Flash chromatography using 20% ethyl acetate in petroleum
−
1
in petroleum ether). mmax/cm 2930 (C–H), 1669 (C=O); d
H
ether as eluent gave the title compound 14 (95 mg, 83%) as a
(
(
d
3
1
300 MHz; CDCl
4H, m, 2 × CH ), 2.02–1.94 (2H, m, CH
(75 MHz; CDCl ) 200.1, 159.3, 142.5 (C), 126.5, 125.7 (CH),
7.2, 30.4 (CH ), 27.8 (CH ), 22.8 (CH ), 20.6 (CH ); m/z (ES+)
51 ([M + H] , 100%); found 151.1111, C10 15O requires 151.1117.
3
) 5.89 (1H, s, CH), 5.75 (1H, s, CH), 2.37–2.34
−
1
colourless oil. mmax/cm 3446 br (OH), 2933 (C–H), 1733 (C=O);
(300 MHz; CDCl
) 5.54–5.42 (1H, dq, J = 6.0 and 15.6 Hz,
CH=CHCH ), 5.29 (1H, dq, J = 1.5 and 15.6 Hz, CH=CHCH
),
.19 (1H, t, J = 4.5 Hz, C(3)H), 2.45–2.35 (1H, m, CH), 2.29–2.14
3H, m, 2 × CH and OH), 1.96–1.84 (1H, m, CH), 1.65 (3H, dd,
J = 1.5 and 6.0 Hz, CHCH ), 1.09 (3H, s, CH ); d (75 MHz;
CDCl ) 219.0 (C), 131.2, 126.8, 77.0 (CH), 56.7 (C), 34.1, 27.4
CH ), 18.2, 15.7 (CH
55 ([M + H] , 70), 137 ([M − OH] , 95); found 155.1068, C
requires 155.1067.
2
2
), 1.86 (6H, s, 2 × CH );
3
d
H
3
C
3
3
3
2
3
2
3
4
(
+
H
3
3
C
(
± )-(2S,3R)-2-Ethyl-3-hydroxy-2-methylcyclopentanone (16)
± )-(2S,3R)-3-Hydroxy-2-methyl-2-vinylcyclopentanone
3
2
3
+
(
1
2
3
); m/z (ES+) 178 ([M + H + Na] , 55%),
(
(
11
+
+
9
H
15
O
2
59 mg, 0.42 mmol) was dissolved in methanol (4.5 mL), 10%
Pd/C (6 mg) added, and the reaction stirred under an atmosphere
of hydrogen for 2 h. The reaction mixture was filtered through
Celite and evaporated under reduced pressure to give the title
compound (55 mg, 92%) as a colourless oil, R 0.08 (10% ethyl
acetate in petroleum ether). The compound displayed comparable
data to the literature:
ꢀ
R
(
± )-(2S,3R)-3-Hydroxy-2-methyl-2-((Z)-prop-1-enyl)cyclopenta-
none (15)
f
Flash chromatography using 20% ethyl acetate in petroleum ether
as eluent gave the title compound 15 (47 mg, 90%) as a colourless
10
d
H
(300 MHz; C
6
D
6
) 3.69 (1H, t, J =
5
.4 Hz, C(3)H), 2.20–2.07 (1H, m, CH), 1.82–1.62 (3H, m, 2 ×
CH and OH), 1.52–1.39 (1H, m, CH), 1.31–1.18 (2H, m, 2 ×
CH), 0.94 (3H, s, CH CH ); d
) 221.4 (C), 75.2 (CH), 53.5 (C), 34.7, 27.7, 27.6
), 14.4, 8.3 (CH ).
−
1
oil, R
br (OH), 3013 (C–H), 2934 (C–H), 1732 (C=O); d
CDCl
f
0.26 (20% ethyl acetate in petroleum ether). mmax/cm 3445
(300 MHz;
) 5.60–5.49 (1H, dq, J = 7.4 and 11.4 Hz, CH=CHCH
),
.14 (1H, dq, J = 1.5 and 11.4 Hz, CH=CHCH
), 4.22 (1H, t, J =
.2 Hz, C(3)H), 2.39–2.15 (4H, m, 3 × CH and OH), 1.94–1.83
), 1.19
) 218.2 (C), 129.9, 129.1, 78.1
), 15.6, 14.4 (CH ); m/z (ES+) 178
H
), 0.73 (3H, t, J = 7.5 Hz, CH
3
2
3
C
3
3
(75 MHz; CDCl
CH
3
5
4
3
(
2
3
(
(
(
(
1H, m, CH), 1.60 (3H, dd, J = 1.5 and 7.4 Hz, CHCH
3H, s, CH ); d (75 MHz; CDCl
CH), 55.7 (C), 33.6, 27.3 (CH
3
(
± )-1-Methyl-2-vinyl-6-oxabicyclo[3.1.0]hexan-2-ol (4)
3
C
3
2
3
Vinylmagnesium bromide (1.0 M, 5.6 mL, 5.6 mmol) was
slowly added to a solution of 2-methylcyclopentanone (0.5 mL,
5.09 mmol) in tetrahydrofuran (25 mL) at −78 C under an
2
3
+
+
+
[M + H + Na] , 75%), 155 ([M + H] , 35), 137 ([M − OH] ,
00); found 155.1076, C requires 155.1067.
◦
1
9
H
15
O
2
This journal is © The Royal Society of Chemistry 2006
Org. Biomol. Chem., 2006, 4, 4144–4148 | 4147