Fraser et al.
93
CH3(CH2)4), 1.51 (s, 3H, C(CH3)3), 1.34 (s, 6H, C(CH3)3),
0.84 (m, 3H, CH3(CH2)4). 13C NMR (63 MHz, CDCl3) δ:
*198.42, 197.69, *155.42, 155.03, *138.59, 138.12, 135.81,
*132.60, 132.32, 128.06, 127.58, 127.52, 126.70, 126.18,
80.03, 59.92, 58.07, *47.76, 47.09, 37.76, 31.23, 28.23,
*27.73, 26.02, *25.32, 22.26, *22.11, 13.72, *13.57. ES-MS
m/e: 396 [M + 1, 100]. Anal. calcd. for C25H33NO3: C 75.92,
CH2CH2CO), 1.48 (s, 4.5H,C(CH3)3), 1.47 (s, 4.5H,
C(CH3)3), 1.4–1.1 (m, 10H, CH3CH2CH2CH2CH2CO and
CH3CH2CH2CH2CH2CHN), 1.0–0.8 (m, 6H, CH3(CH2)4CO
and CH3(CH2)4CHN). 13C NMR (63 MHz, CDCl3) δ:
*208.62, 208.15, *155.77, 154.91, 79.64, *79.31, 64.43,
62.51, *39.18, 38.77, 30.98, 30.60, *29.76, 27.79, 26.67,
*26.21, 25.10, 22.90, *22.79, *22.03, 21.94, 13.41, *13.35.
ES-MS m/e: 314 [M + 1, 100]. Anal. calcd. for C18H35NO3:
C 68.97, H 11.25, N 4.47; found: C 68.79, H 11.12, N 4.32.
1
H 8.41, N 3.54; found: C 76.03, H 8.48, N 3.61. The H
NMR (200 MHz, DMSO-d6) signal for CHN coalesced at or
‡
below 352 K. The barrier to rotation (∆Gc ) was estimated to
be 17.2 kcal/mol.
4-(N-tert-Butoxycarbonyl-N-methylamino)-2-methyl-3-
nonanone (3k)
2-(N-Benzyl-N-tert-butoxycarbonylamino)-3-octanone (3h)
Aminoalcohol 2h was prepared from stannane 1f and
hexanal according to General procedure A in 67% yield as a
clear colourless oil. TPAP oxidation of 2h gave ketone 3h in
90% yield as a viscous clear oil. IR (neat) (cm–1): 2934,
Aminoalcohol 2k was prepared according to General pro-
cedure A from stannane 1d and isobutyraldehyde in 77%
yield as a mixture of diastereomers. The title compound was
prepared from alcohol 2k in 94% yield as a clear colourless
oil. IR (neat) (cm–1): 2928, 1701, 1461, 1380, 1154. 1H
NMR (250 MHz, CDCl3) δ: 4.86 (dd, 0.5H, J = 5.7, 9.1 Hz,
CHN), 4.52 (dd, 0.5H, J = 4.9, 9.6 Hz, CHN), 2.95–2.75 (m,
1H, CH3CHCH3), 2.74 (s, 1.5H, CH3N), 2.67 (s, 1.5H,
CH3N), 1.9–1.5 (m, 2H, CH2CHN), 1.48 (s, 9H, C(CH3)3),
1.40–1.15 (br m, 6H, CH3CH2CH2CH2), 1.15–1.00 (m, 6H,
CH3CHCH3), 1.0–0.8 (br m, 3H, CH3(CH2)4). 13C NMR
(63 MHz, CDCl3) δ: *212.16, 211.68, *155.71, 154.93,
79.73, *79.39, 61.88, 60.29, *36.93, 36.23, 31.04, 30.30,
*29.68, 27.84, 26.75, *26.39, 25.10, 22.08, 18.63, *18.42,
*17.34, 17.23, 13.47. ES-MS m/e: 286 [M + 1, 100].
1
1702, 1416, 1367, 1249, 1163. H NMR (250 MHz, CDCl3)
δ: 7.4–7.1 (m, 5H, ArH), 4.9–4.5 (m, 1.1H, ArCH2N), 4.3–
4.1 (m, 1.3H, ArCH2N and CHN), 3.7–3.5 (m, 0.6H, CHN),
2.4–1.9 (m, 2H, CH2C(O)), 1.5–1.0 (m, 9H, CH3CHN and
CH3(CH2)3CH2), 1.43 (s, 9H, C(CH3)3), 0.85 (m, 3H,
CH3(CH2)4) 13C NMR (63 MHz, CDCl3) δ: 208.84, *208.12,
154.93, 138.70, *137.90, 128.44, 127.50, 127.27, *80.98,
80.49, *61.19, 60.37, *51.09, 49.75, 38.54, *37.97, 31.27,
28.15, 23.28, 22.24, *13.77, 13.57. ES-MS m/e: 334 [M + 1,
100]. Anal. calcd. for C20H31NO3: C 72.04, H 9.37, N 4.20;
found: C 72.08, H 9.50, N 4.15.
4-(N-tert-Butoxycarbonyl-N-methylamino)-2,2-dimethyl-3-
nonanone (3l)
4-(N-tert-Butoxycarbonyl-N-methylamino)-3-nonanone
(3i)
Aminoalcohol 2l was prepared according to General pro-
cedure A from stannane 1d and pivaldehyde in 78% yield as
a mixture of diastereomers. The title compound was pre-
pared from alcohol 2l in 84% yield as a clear colourless oil.
Aminoalcohol 2i was prepared according to General pro-
cedure A from stannane 1d and propionaldehyde in 70%
yield as a mixture of diastereomers. The title compound was
prepared from aminoalcohol 2i in 87% yield as a clear
colourless oil. IR (neat) (cm–1): 2926, 1701, 1460, 1355,
1
IR (neat) (cm–1): 2927, 1696, 1462, 1380, 1320, 1154. H
NMR (250 MHz, CDCl3) δ: 5.24 (apparent t, 0.6H, J =
7.5 Hz, CHN), 5.04 (dd, 0.4H, J = 5.6, 9.4 Hz, CHN), 2.70
(s, 1H, CH3N), 2.66 (s, 2H, CH3N), 1.70–1.40 (m, 2H,
CH2CHN), 1.50 (s, 3H, OC(CH3)3), 1.46 (s, 6H, OC(CH3)3),
1.40–1.20 (m, 6H, CH3(CH2)3CH2), 1.16 (s, 3H,
COC(CH3)3), 1.15 (s, 6H, COC(CH3)3), 0.95–0.80 (br m,
3H, CH3(CH2)4). 13C NMR (63 MHz, CDCl3) δ: *212.49,
211.85, *155.13, 154.51, 79.58, *79.21, 55.80, 54.49, 43.61,
*31.12, 31.00, 28.53, 28.24, 27.88, 25.84, *25.54, 24.83,
22.09, 13.50. ES-MS m/e: 300 [M + 1, 100]. Anal. calcd. for
C17H33NO3: C 68.19, H 11.11, N 4.68; found: C 68.40, H
10.90, N 4.73.
1
1150. H NMR (250 MHz, CDCl3) δ: 4.66 (dd, 0.55H, J =
5.1, 9.9 Hz, CHN), 4.27 (dd, 0.45H, J = 4.9, 10.0 Hz, CHN),
2.77 (s, 1.4H, CH3N), 2.69 (s, 1.6H, CH3N), 2.6–2.3 (m, 2H,
CH3CH2CO), 1.95–1.45 (m, 2H, CH2CHN), 1.49 (s, 5H,
C(CH3)3), 1.47 (s, 4H, C(CH3)3), 1.4–1.15 (m, 6H,
CH3(CH2)3CH2CHN), 1.15–0.95 (overlapping t, 3H, J =
7.2 Hz, COCH2CH3), 0.95–0.8 [m, 3H, CH3(CH2)4CHN).
13C NMR (63 MHz, CDCl3) δ: *209.16, 208.63, *155.79,
154.91, 79.71, *79.38, 64.41, 62.54, *32.38, 31.98, 30.99,
30.79, *29.87, 27.82, 26.81, *26.32, 25.12, 22.04, 13.44,
7.14. ES-MS m/e: 272 [M + 1, 100]. Anal. calcd. for
C15H29NO3: C 66.38, H 10.77, N 5.16; found: C 66.22, H
10.55, N 4.96.
3-(N-tert-Butoxycarbonyl-N-methylamino)-2-methyl-4-
nonanone (3m)
7-(N-tert-Butoxycarbonyl-N-methylamino)-6-dodecanone
(3j)
Aminoalcohol 2m was prepared according to General
procedure A from stannane 1b and hexanal in 65% yield as a
mixture of diastereomers. The title compound was prepared
from alcohol 2m in 80% yield as a clear colourless oil. IR
(neat) (cm–1): 2945, 1695, 1457, 1379, 1304, 1154. 1H NMR
(250 MHz, CDCl3) δ: 4.44 (d, 0.6H, J = 10.8 Hz, CHN),
4.07 (d, 0.4H, J = 10.4 Hz, CHN), 2.69 (s, 1.2H, CH3N),
2.62 (s, 1.8H, CH3N), 2.6–2.25 (m, 2H, CH2CO), 2.25–2.1
(m, 1H, CHCHN), 1.55–1.45 (m, 2H, CH2CH2CO), 1.49 (s,
3.6H, C(CH3)3), 1.48 (s, 5.4H, C(CH3)3), 1.4–1.15 (m, 4H,
CH2(CH2)2CH3), 1.0–0.75 (m, 9H, (CH3)2CH and
Aminoalcohol 2j was prepared according to General pro-
cedure A from stannane 1d and hexanal in 66% yield as a
mixture of diastereomers. The title compound was prepared
from aminoalcohol 2j in 82% yield as a clear colourless oil.
1
IR (neat) (cm–1): 2943, 2866, 1702, 1459, 1389, 1155. H
NMR (250 MHz, CDCl3) δ: 4.66 (dd, 0.5H, J = 5.3, 9.8 Hz,
CHN), 4.27 (dd, 0.5H, J = 4.7, 9.8 Hz, CHN), 2.76 (s, 1.5H,
CH3N), 2.68 (s, 1.5H, CH3N), 2.41 (t, 2H, J = 7.3 Hz,
CH2CO), 1.9–1.7 (m, 2H, CH2CHN), 1.7–1.5 (m, 2H,
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