D.-S. Lee / Tetrahedron: Asymmetry 20 (2009) 2014–2020
2019
Table 3
The electrolysis of compounds 2 and 3
O
O
O
n
OH
n
O
n
OH
b
N
N
or
EtO
N
2
3
= n = 0
= n = 1
9 = n = 0
10 = n = 0
12 = n = 1
11 = n = 1
Entry
Substrate
Current ampere (A)
Electric charge (Faraday)
Product (Yield%)
Recovery yield (%)
Ratioa R/S
1
2
3
4
5
6
7
8
9
2
2
2
2
2
2
2
3
3
0.100
0.100
0.100
0.100
0.075
0.150
0.200
0.100
0.100
5.00
6.00
6.50
7.00
7.00
7.00
7.00
3.50
7.00
10 (50)
10 (49)
10 (56)
10 (74)
10 (32)
10 (58)
10 (60)
11 (0)
2 (32)
2 (11)
2 (9)
2 (0)
2 (21)
2 (0)
2 (0)
3 (93)
3 (50)
25/75
25/75
25/75
25/75
25/75
25/75
30/70
—
11 (40)
40/60
a
The ratio was analyzed by 400 MHz NMR spectrum.
4
.3.2. (S)-3-Hydroxy-1-(piperidin-1-yl)butan-1-one 3
Yield 62%; pale orange oil; [ = +61.6 (c 2.87, CHCl
400 MHz, CDCl ) d = 1.22 (d, J = 6.4 Hz, 3H), 1.52–1.71 (m, 6H),
(51.4). HRMS (EI): m/z calcd for C14
237.1724.
H23NO
2
: 237.1719; found:
1
a]
D
3
); H NMR
(
3
2
3
.29 (dd, J = 16.4, 9.6 Hz, 1H), 2.48 (dd, J = 16.4, 2.4 Hz, 1H), 3.36–
4.4.3. (1S,4R,6R,8R)-3-Ethyl-4,11,11-trimethyl-5-oxa-3-aza-
1
,6
.39 (m, 2H), 3.50–3.62 (m, 2H), 4.18–4.23 (m, 1H), 4.45 (s, 1H).
tricyclo[6.2.1.0 ]undecan-2-one 7bR
Yield 22%; colorless oil; [
= À10.3 (c 1.99, CHCl
(400 MHz, CDCl ) d = 1.04 (s, 3H), 1.05 (s, 3H), 1.10 (t, J = 7.2 Hz,
1
3
); 1H NMR
3
C NMR (100 MHz, CDCl
3
) d = 22.12, 24.38, 25.44, 26.25, 40.64,
a]
D
4
2.41, 46.27, 64.18, 170.70. MS (EI) m/z (%): 171.1 (39.2); 126.1
3
(
C
57.6); 112.1 (45.1); 84.1 (100.0). HRMS (EI): m/z calcd for
H17NO : 171.1252; found: 171.1255.
9 2
3H), 1.41 (d, J = 5.6 Hz, 3H), 1.66–1.91 (m, 6H), 2.20–2.26 (m,
1H), 2.73 (sextet, J = 6.8 Hz, 2H), 3.84 (sextet, J = 6.8 Hz, 1H), 4.14
1
3
(
dd, J = 8.0, 3.2 Hz, 1H), 4.99 (q, J = 5.6 Hz, 1H). C NMR (100
MHz, CDCl ) d = 13.12, 19.26, 20.49, 21.63, 27.75, 28.28, 37.27,
8.04, 44.83, 50.79, 52.63, 75.64, 83.29, 168.72. MS (EI) m/z (%):
37.2 (37.8); 222.2 (100.0); 149.1 (76.9); 121.1 (70.8). HRMS
: 237.1717; found: 237.1723.
4
.4. General procedure for anodic oxidation
3
3
2
4 4
A solution of tertiary amido alcohol 1 (1 equiv) and Et NBF
(
EI): m/z calcd for C14H23NO
2
(
3
2 equiv) in EtOH/CH CN (1:1, 50 mL) was placed in a 50 mL bea-
ker. This mixture was electrolyzed under constant current ampere
through a platinum plate anode (3.0 cm  5.0 cm) and platinum
cathode (3.0 cm  5.0 cm). The solvent was removed under re-
duced pressure. The electrolyte was filtered out and rinsed with
EtOAc. The filtrate was concentrated under reduced pressure to
afford the crude product which was purified by column chro-
matography.
4
.4.4. (1S,4S,6R,8R)-3-Propyl-4-ethyl-11,11-dimethyl-5-oxa-3-
1
,6
aza-tricyclo[6.2.1.0 ]undecan-2-one 7cS
Yield 43%; colorless oil. [ = -46.45 (c 2.28, CHCl
400 MHz, CDCl ) d = 0.88 (t, J = 7.2 Hz, 3H), 0.93 (t, J = 7.2 Hz,
H), 1.11 (s, 6H), 1.44–1.99 (m, 10H), 2.24–2.32 (m, 1H), 2.99–
.06 (m, 1H), 3.68–3.76 (m, 2H), 4.81 (dd, J = 5.6, 2.4 Hz, 1H). 13
) d = 7.39, 11.40, 21.12, 21.45, 21.52, 26.56,
a]
D
); 1H NMR
3
(
3
3
3
C
NMR (100 MHz, CDCl
3
2
1
1
2
7.79, 29.18, 37.50, 43.00, 44.82, 50.18, 53.37, 81.46, 87.58,
71.15. MS (EI) m/z (%): 265.2 (9.8); 236.2 (100.0); 149.1 (45.3);
21.1 (58.1). HRMS (EI): m/z calcd for C16H27NO : 265.2030; found:
2
65.2036.
4
.4.1. Compound 7aS
Yield 67%; white solid; mp = 112–114 °C; [
a
]
D
= À47.7 (c 2.99,
1
CHCl
1
3
); H NMR (400 MHz, CDCl
3
) d = 1.10 (s, 3H), 1.12 (s, 3H),
.37–1.42 (m, 2H), 1.69–1.99 (m, 10H), 2.29–2.46 (m, 2H), 3.78
(
dd, J = 8.0, 3.2 Hz, 1H), 4.62 (dd, J = 8.0, 3.2 Hz, 1H), 4.71 (d,
4
.4.5. (1S,4R,6R,8R)-3-Propyl-4-ethyl-11,11-dimethyl-5-oxa-3-
1
3
J = 14 Hz, 1H). C NMR (100 MHz, CDCl
3
) d = 20.95, 21.51, 22.38,
1,6
aza-tricyclo[6.2.1.0 ]undecan-2-one 7cR
2
8
2
C
4.82, 27.71, 28.62, 33.08, 37.62, 39.91, 44.81, 50.17, 53.76,
0.76, 86.25, 169.71. MS (EI) m/z (%): 249.2 (44.2); 221.2 (28.6);
07.1 (34.5); 84.1 (100.0); 55.0 (35.5). HRMS (EI): m/z calcd for
Yield 31%; white solid; mp = 84–86 °C; [
a
]
D
= +23.5 (c 2.50,
1
CHCl
3
3
); H NMR (400 MHz, CDCl ) d = 0.92 (t, J = 7.2 Hz, 3H), 0.96
(
t, J = 7.2 Hz, 3H), 1.10 (s, 3H), 1.11 (s, 3H), 1.56–1.97 (m, 10H),
15
2
H23NO : 249.1725; found: 249.1727.
2
(
.22–2.32 (m, 1H), 2.54–2.61 (m, 1H), 3.81–3.88 (m, 1H), 4.03
dd, J = 8.0, 3.2 Hz, 1H), 4.66 (dd, J = 10.4, 3.2 Hz, 1H). 13C NMR
4
.4.2. (1S,4S,6R,8R)-3-Ethyl-4,11,11-trimethyl-5-oxa-3-aza-
(100 MHz, CDCl ) d = 9.16, 11.44, 20.63, 21.26, 21.69, 24.97,
27.81, 28.36, 37.21, 44.99, 45.30, 50.91, 52.74, 75.33, 88.58,
169.14. MS (EI) m/z (%): 265.2 (0.7); 236.2 (100.0); 149.1 (64.0);
121.1 (72.0). HRMS (EI): m/z calcd for C16H27NO : 265.2047; found:
3
1
,6
tricyclo[6.2.1.0 ]undecan-2-one 7bS
Yield 64%; colorless oil; [
= À23.8 (c 3.53, CHCl
400 MHz, CDCl ) d = 1.00 (s, 3H), 1.10 (s, 3H), 1.14 (t, J = 6.8 Hz,
H), 1.45 (d, J = 5.6 Hz, 3H), 1.72–1.98 (m, 6H), 2.26–2.32 (m,
H), 3.42 (nonet, J = 6.8 Hz, 2H), 3.77 (dd, J = 8.0, 3.2 Hz, 1H), 4.95
a]
D
3
); 1H NMR
(
3
1
3
2
265.2044.
1
3
(
q, J = 5.6 Hz, 1H). C NMR (100 MHz, CDCl
3
) d = 14.25, 20.92,
4.4.6. Compound 7dS
Yield 62%; colorless oil; [a
3
]D = +12.0 (c 2.18, CHCl ); 1H NMR
2
8
1
1.42, 21.57, 27.80, 28.69, 36.63, 37.57, 44.83, 50.24, 53.13,
1.45, 84.41, 170.21. MS (EI) m/z (%): 237.2 (91.6); 222.2 (53.1);
93.2 (59.3); 164.1 (50.5); 149.1 (52.6); 121.1 (100.0); 72.1
(400 MHz, CDCl ) d = 1.10 (s, 3H), 1.12 (s, 3H), 1.75–2.29 (m,
11H), 3.42–3.48 (m, 1H), 3.63–3.70 (m, 1H), 3.88 (dd, J = 8.0,
3