3-Cyclohexyl-oxirane-carboxylic-acid-methylester (2)20. This
compound was prepared according to method A as colourless
oil in 98% yield (83 mg, 0.49 mmol). mmax (neat)/cm−1 1746; dH
(400 MHz, CDCl3) 1.15–1.26 (5H, m, Cy), 1.69–1.77 (6H, m,
Cy), 2.99 (1H, dd, J = 6.4 Hz, J = 2.0 Hz, CHCy), 3.29 (1H,
d, J = 2.0 Hz, CHCO), 3.79 (3H, s, CO2CH3). dC (101 MHz,
CDCl3) 25.4 (CH2), 25.5 (CH2), 26.1 (CH2), 28.8 (CH2), 29.3
(CH2), 39.5 (CH), 51.9 (CH3), 52.4 (CH), 62.6 (CH), 170.1 (CO).
GC-analysis: tR (R): 79.51; tR (S): 79.98.
(1S,3S,4R)-2-tert-Butyloxymethyl-3-[(1S,4R)-7,7-dimethyl-2-
oxobicyclo[2.2.1]hept-1-yl]-2-thioniabicyclo[2.2.1]heptane tetra-
fluoroborate (6b). To a stirred solution of the chiral sulfide
A (1.02 g, 4.03 mmol) in 1.4 ml DCM was added a-bromo-
tert-butyl-acetate (4.55 ml, 28.2 mmol) in one portion. 3.096 g
(28.2 mmol) of NaBF4 dissolved in 4 ml water (saturated
solution) were added and the reaction mixture was stirred
vigorously at rt and monitored by TLC for two days. After
consumption of the sulfide, the reaction mixture was diluted
with DCM and water. The resulting phases were separated
and the water layer was washed with DCM (3 × 10 ml). The
combined organic washings were washed with brine (1 × 15 ml),
dried over MgSO4, filtered and the solvent was evaporated
under a vacuum to yield 1.50 g (3.35 mmol, 83% of the theory)
of a white crystalline product. Rf = 0.03 (6 : 4 petrol–EtOAc);
(found: M+, 365.2143 C21H33O3S requires 365.2145); mp
102–103 ◦C; mp 104–105 ◦C; [a]2D3 = −53.4 (c = 1.0); (found C,
55.74; H, 7.33%; C21H33BF4O3S requires C, 55.76; H, 7.33%);
mmax (neat)/cm−1 2967, 1733, 1041; dH (500 MHz, CD3OD,
TOCSY, Jres.COSY) 1.02 (6H, s, C16H3), 1.39 (1H, m, C5HH),
1.39 (9H, s, C18H3), 1.54–1.67 (2H, m, C9H2), 1.75 (1H, ddd,
J = 13.2 Hz, J = 8.9 Hz, J = 4.0 Hz, C5HH), 1.90 (1H, d, J =
18.6 Hz, C2HH), 1.93 (1H, m, C4HH), 2.00 (1H, m, C4HH),
2.07 (1H, t, J = 4.5 Hz, C3HH), 2.09–2.14 (2H, m, C10H2),
2.19 (1H, dt, J = 12.6 Hz, J = 2.1 Hz, C12HH), 2.25 (1H, t,
J = 12.8 Hz, C12HH), 2.56 (1H, ddd, J = 18.6 Hz, J = 4.9 Hz,
J = 2.8 Hz, C2HH), 3.12 (1H, br. s, C8H), 4.02 (1H, dd, J =
3.4 Hz, J = 1.5 Hz, C7H), 4.33 (1H, br. s, C11H). dC (125 MHz,
CD3OD) 19.8 (CH3), 22.4 (CH3), 25.6 (CH2), 27.7 (CH2), 27.9
(CH2), 28.3 (3 × CH3), 35.1 (CH2), 42.1 (CH2), 44.8 (CH), 45.0
(CH2), 46.8 (CH), 49.8 (CH2), 51.2 (C), 61.5 (C), 61.6 (CH),
70.8 (CH), 86.8 (C), 165.2 (CO), 217.2 (CO).
3-Butyl-oxirane-2-carboxylic-acid-methylester (3)20. This com-
pound was prepared according to method A as colourless oil
in 73% yield (58 mg, 0.37 mmol). mmax (neat)/cm−1 2975, 2929,
2862, 1758, 1742; dH (400 MHz, CDCl3) 0.93 (3H, t, J = 7.3 Hz,
CH3CH2), 1.31–1.69 (6H, m, CH2), 3.16 (1H, m, CH2CHO),
3.23 (1H, d, J = 1.9 Hz, CHOCO2), 3.79 (3H, s, CO2CH3). dC
(101 MHz, CDCl3) 13.9 (CH3), 22.4 (CH2), 27.8 (CH2), 31.2
(CH2), 52.4 (CH3), 53.0 (CH), 58.6 (CH), 170.0 (CO).
3,4-(Trifluoromethyl-phenyl)-oxirane-2-carboxylic-acid-methyl-
ester (4)21. This compound was prepared according to method
A as colourless oil in 75% yield (92 mg, 0.38 mmol). dH
(400 MHz, CDCl3) 3.49 (1H, d, J = 1.7 Hz, PhCH), 3.83 (3H, s,
CO2CH3), 4.17 (1H, d, J = 1.5 Hz, CH), 7.42 (2H, d, J =
8.3 Hz, CF3CCHCH), 7.63 (2H, d, J = 8.3 Hz, CF3CCH). dC
(101 MHz, CDCl3) 52.7 (CH3), 56.7 (CH), 57.1 (CH), 125.7
(C), 126.1 (2 × CH), 131.2 (CF3, JCF = 33.1 Hz), 138.9 (C),
168.1 (CO).
1-Oxa-spira[2,5]octane-2- carboxylic-acid-methylester (5)8,22
.
This compound was prepared according to method A as
colourless oil [bp 138–142 ◦C; 20 mbar] in 68% yield (58 mg,
0.34 mmol). dH (400 MHz, CDCl3) 1.38–1.78 (10H, m, Cy), 3.27
(1H, s, CHO), 3.71 (3H, s, CH3). dC (101 MHz, CDCl3) 24.8
(CH2), 25.0 (CH2), 25.3 (CH2), 28.8 (CH2), 34.9 (CH2), 52.2
(CH3), 59.4 (CH), 64.9 (C), 168.9 (CO)..
(1S,3S,4R)-2-tert-Butyloxymethyl-3-[(1S,4R)-7,7-dimethyl-2-
oxobicyclo[2.2.1]hept-1-yl]-2-thioniabicyclo[2.2.1]heptane hexa-
fluorophosphate (6c). To a stirred solution of the chiral sulfide
A (507 g, 2.00 mmol) in 1.4 ml DCM was added a-bromo-
tert-butyl-acetate (2.28 ml, 14.1 mmol) in one portion. An
aqueous solution of KPF6 (2.590 g, 14.1 mmol) in 4 ml water
was added and the reaction mixture was stirred vigorously at
rt and monitored by TLC for four days. After consumption
of the sulfide, the reaction mixture was diluted with DCM
and water. The resulting phases were separated and the water
layer was washed with DCM (3 × 20 ml). The combined
organic washings were washed with brine (1 × 15 ml), dried
over MgSO4, filtered and the solvent was evaporated under a
vacuum to yield 772 mg (1.70 mmol, 85% of the theory) of an
(1S,3S,4R)-2-tert-Butyloxymethyl-3-[(1S,4R)-7,7-dimethyl-
2-oxobicyclo[2.2.1]hept-1-yl]-2-thioniabicyclo[2.2.1]heptane bro-
mide (6a). To a stirred suspension of sulfide A (253 g,
1.00 mmol) in 1.4 ml of DCM and 2 ml of water was added
a-bromo-tert-butyl-acetate (1.14 ml, 4.00 mmol) in one portion.
The reaction mixture was stirred vigorously at rt and monitored
by TLC for two days. After consumption of the sulfide, the
reaction mixture was diluted with DCM and water (20 ml each).
The resulting phases were separated, and the water layer was
washed with DCM (3 × 10 ml). The combined organic washings
were washed with brine (1 × 15 ml), dried over MgSO4, filtered
and the solvent was evaporated under a vacuum to yield 351 mg
(0.79 mmol, 79% of the theory) of a white solid. Rf = 0.11
23
off-white solid. Rf = 0.05 (9 : 1 DCM–MeOH); [a]D = −60.0
(c = 1.0); (found: M+, 365.2148; C21H33O3S requires 365.2150);
mp 101–102 ◦C; mmax (neat)/cm−1 3002, 2967, 1733, 1726, 1042;
dH (400 MHz, CD3OD) 1.12 (3H, s, C16H3), 1.22 (3H, s, C16H3),
1.40–1.54 (10H, m, 3 × C18H3, C5HH), 1.64–1.73 (3H, m,
C5HH, C9H2), 2.00 (1H, d, J = 18.8 Hz, C2HH), 2.11–2.27 (6H,
m, C4H2, C3H, C10H2, C12HH), 2.34 (1H, m, C12HH), 2.57–2.64
(1H, ddd, J = 18.8 Hz, J = 4.6 Hz, J = 2.2 Hz, C2HH), 3.18
(1H, br. s, C8H), 3.87 (1H, d, J = 17.7 Hz, C13HH), 4.22 (1H,
d, J = 17.7 Hz, C13HH), 4.23 (1H, br. s, C7H), 4.42 (1H, d, J =
5.1 Hz, C11H). dC (101 MHz, CDCl3) 19.1 (CH3), 21.9 (CH3),
24.3 (CH2), 26.7 (CH2), 26.8 (CH2), 27.8 (3 × CH3), 33.4 (CH2),
40.8 (CH2), 43.1 (CH), 44.0 (CH2), 45.0 (CH), 45.7 (CH2), 50.1
(C), 59.6 (C), 60.2 (CH), 68.2 (CH), 86.5 (C), 163.3 (CO), 215.6
(CO).
(75 : 25 petrol–EtOAc); mp 104–105 ◦C; [a]23 = −48.0 (c =
D
1.0); (found: M+, 365.2148 C21H33O3S requires 365.2150); mmax
(neat)/cm−1 3002, 2967, 1733, 1042; dH (401 MHz, CDCl3)
1.12 (3H, s, C16H3), 1.23 (3H, s, C16H3), 1.39–1.53 (10H, m,
C5HH, C18H3), 1.55–1.78 (3H, m, C5HH, C9H2), 1.98 (1H, d,
J = 18.6 Hz, C2HH), 2.09–2.38 (6H, m, C3HH, C4H2, C10H2,
C12HH), 2.60 (1H, dd, J = 18.6 Hz, J = 3.7 Hz, C2HH), 2.75
(1H, br. d, J = 13.2 Hz, C12HH), 3.19 (1H, br. s, C8H), 3.95 (1H,
d, J = 17.1 Hz, C13HH), 4.36 (1H, dd, J = 17.1 Hz, C13HH),
4.42 (1H, br. s, C7H), 4.46 (1H, d, J = 5.4 Hz, C11HH). dC
(125 MHz, CD3OD) 19.2 (CH3), 22.9 (CH3), 24.3 (CH2), 26.7
(CH2), 26.8 (CH2), 27.8 (3 × CH3), 33.2 (CH2), 40.8 (CH2), 43.1
(CH), 44.0 (CH2), 45.0 (CH), 45.6 (CH2), 50.0 (C), 59.6 (C),
60.2 (CH), 67.4 (CH), 86.1 (C), 163.5 (CO), 215.7 (CO).
1 4 2 4
O r g . B i o m o l . C h e m . , 2 0 0 5 , 3 , 1 4 1 9 – 1 4 2 7