PAPER
O-Allyl Oximes from a-Chloronitroso Compounds
13C NMR (CD2Cl2): d = 136.3, 42.1, 40.2, 27.5, 25.7, 19.9.
3569
MS (GC-MS): m/z (%) = 230 (2), 117 (100), 115 (20), 105 (5), 91
(10), 77 (5).
MS: m/z (%) = 168 (6), 160 (4), 158 (13), 145 (14), 143 (43), 137
(53), 133 (4), 131 (13), 123 (25), 107 (18), 105 (19), 103 (53), 97
(15), 95 (37), 91 (15), 83 (24), 81 (38), 79 (18), 77 (25), 69 (100),
67 (37), 57 (35), 55 (45), 43 (25), 41 (72).
Anal. Calcd for C15H19NO (229.32): C, 78.56; H, 8.35; N, 6.11.
Found: C, 78.40; H, 8.33; N, 6.12.
N-(But-1-en-3-yl)hydroxylamine Hydrochloride (18a)
Mp 58–61 °C.
Anal. Calcd for C12H18ClNO (203.71): C, 58.96; H, 8.61; N, 6.88.
Found: C, 58.94; H, 8.66; N, 6.81.
IR (KBr): 3465, 3040, 2507, 1633, 1450, 1426, 1381, 1003, 947
cm–1.
1H NMR (DMSO-d6): d = 10.39 (br, 2 H), 5.84 (ddd, 1 H, J = 17.4,
10.5, 7.4 Hz), 5.32 (ddd, 1 H, J = 17.4, 2.4, 1.2 Hz), 5.28 (ddd, 1 H,
J = 10.5, 2.4, 1.2 Hz), 3.68 (dtq, 1 H, J = 7.4, 1.2, 6.6 Hz), 1.14 (d,
3 H, J = 6.6 Hz).
Reaction of But-2-enylzinc Bromide (15a) with 1-Chloro-1-
nitroso-2,2,6,6-tetramethylcyclohexane (6b)
In THF: A solution of 1-chloro-1-nitroso-2,2,6,6-tetramethylcyclo-
hexane (6b; 0.35 g, 1.71 mmol) in anhyd THF (10 mL) was cooled
to –78 °C and a THF solution of but-2-enylzinc bromide (15a;
5 mL, 1.71 mmol) was added dropwise via syringe. The mixture
was stirred at –78 °C for 1 h, allowed to reach 4 °C during 2.5 h
with TLC and GC monitoring, and then stirred at r.t. for 12 h. The
slightly blue solution was quenched with aq sat. NaHCO3 solution
(5 mL) and the white precipitate formed was dissolved by adding aq
sat. NH4Cl solution (10 mL). Separation of the organic phase, dry-
ing (Na2SO4) and evaporation of solvent in vacuo afforded O-(but-
1-en-3-yl)-2,2,6,6-tetramethylcyclohexanone oxime 22 (0.12 g,
31%) as a colorless oil. A sample of 6b in THF was run in parallel
to monitor its potential photochemical decomposition.18
13C NMR (DMSO-d6): d = 136.4, 123.2, 60.0, 14.8.
MS: m/z (%) = 87 (7), 72 (35), 55 (60), 41 (100), 40 (69), 39 (42).
N-(3-Methylbut-1-en-3-yl)hydroxylamine Hydrochloride (18b)
Mp 60–63 °C.
IR (KBr): 3467, 3037, 2509, 1635, 1448, 1426, 1382, 1010, 948
cm–1.
1H NMR (DMSO-d6): d = 10.41 (br, 2 H), 6.03 (dd, 1 H, J = 17.5,
10.6 Hz), 5.35 (d, 1 H, J = 17.5 Hz), 5.31 (d, 1 H, J = 10.6 Hz), 1.36
(s, 6 H).
In toluene: A similar procedure as above was followed for the reac-
tion of but-2-enylzinc bromide (15a) with 1-chloro-1-nitroso-
2,2,6,6-tetramethylcyclohexane (6b), with the exception that a tol-
uene solution of the organozinc reagent was used; yield: 28%.
13C NMR (DMSO-d6): d = 137.2, 117.5, 61.6, 21.1.
MS: m/z (%) = 101 (6), 86 (11), 84 (5), 74 (8), 69 (53), 46 (15), 41
(100), 40 (30), 39 (25).
O-(But-1-en-3-yl)-2,2,6,6-tetramethylcyclohexanone Oxime
(22)
Colorless oil.
2,2,6,6-Tetramethylcyclohexanone Oxime
A solution of NH2OH·HCl (6.77 g, 97.4 mmol) and NaOAc (8.52 g,
103.87 mmol) in MeOH (120 mL) was stirred for 30 min at r.t.
2,2,6,6-Tetramethylcyclohexanone (5.00 g, 32.46 mmol) was add-
ed and the mixture was refluxed for 3 days. After completion, the
mixture was poured into ice water, the white precipitate was collect-
ed by filtration and washed with cold water. Recrystallization from
MeOH afforded analytically pure 2,2,6,6-tetramethylcyclohex-
anone oxime as white crystals; yield: 4.00 g (73%); mp 154–
155 °C.
IR (neat): 3082, 2959, 2930, 2867, 1645, 1464, 1382, 1362, 1232,
1160, 946 cm–1.
1H NMR (CD2Cl2): d = 5.92 (ddd, 1 H, J = 17.3, 10.6, 5.7 Hz), 5.18
(ddd, 1 H, J = 17.3, 1.5, 1.4 Hz), 5.07 (ddd, 1 H, J = 10.6, 1.5, 1.4
Hz), 4.51 (dtq, 1 H, J = 5.7, 1.4, 6.7 Hz), 1.56–1.60 (m, 2 H), 1.47–
1.50 (m, 4 H), 1.28 (s, 3 H), 1.27 (d, 3 H, J = 6.7 Hz), 1.26 (s, 3 H),
1.16 (s, 3 H), 1.14 (s, 3 H).
13C NMR (CD2Cl2): d = 167.1, 140.7, 114.4, 79.5, 41.4, 38.5, 38.3,
37.1, 31.1, 31.1, 27.5, 27.5, 19.9, 18.0.
IR (KBr): 3304, 2930, 2866, 1646, 1561, 1459, 1381, 1360, 1220,
935 cm–1.
1H NMR (CDCl3): d = 8.74 (br, 1 H), 1.60–1.65 (m, 2 H), 1.51–1.56
(m, 4 H), 1.36 (s, 6 H), 1.21 (s, 6 H).
13C NMR (CDCl3): d = 168.6, 40.5, 37.9, 37.6, 37.0, 30.5, 26.7,
17.4.
MS: m/z (%) = 223 (5), 208 (4), 169 (18), 152 (25), 100 (18), 87 (8),
69 (75), 55 (100), 41 (30), 29 (12), 27 (20).
Anal. Calcd for C14H25NO (223.35): C, 75.28; H, 11.28; N, 6.27.
Found: C, 75.22; H, 11.14; N, 6.20.
MS: m/z (%) = 169 (10), 154 (12), 152 (32), 141 (7), 137 (10), 126
(8), 100 (35), 87 (19), 69 (100), 55 (60), 41 (63), 27 (20).
Acknowledgment
Anal. Calcd for C10H19NO (169.26): C, 70.96; H, 11.31; N, 8.28.
Found: C, 70.93; H, 11.12; N, 8.21.
This project was supported by Deutsche Forschungsgemeinschaft
and Fonds der Chemischen Industrie. S.V.F. was awarded a Ph.D.
grant from Graduiertenkolleg 378/I Mechanistische und Anwen-
dungsaspekte nichtkonventioneller Oxidationsreaktionen, Univer-
sity of Leipzig, which is gratefully acknowledged.
1-Chloro-1-nitroso-2,2,6,6-tetramethylcyclohexane (6b)
A solution of t-BuOCl (3.1 g, 20 mmol, 70% w/w in t-BuOH) in an-
hyd CH2Cl2 (30 mL) was added dropwise during 30 min under N2
and protection against light to a pre-cooled (0 °C) solution of
2,2,6,6-tetramethylcyclohexanone oxime (3.05 g, 18 mmol) in an-
hyd CH2Cl2 (50 mL). After stirring for 1.5vh at 0 °C, the mixture
was warmed-up to r.t. and the solvent was evaporated in vacuo. The
blue residue was recrystallized from MeOH to afford 6b as blue
crystals; yield: 3.23 g (88%); mp 115–117 °C.
References
(1) Present address: Key Organics Ltd., Highfield Industrial
Estate, Camelford, PL32 9QZ, UK.
(2) Adam, W.; Krebs, O. Chem. Rev. 2003, 103, 4131.
(3) (a) Leach, A. G.; Houk, K. N. J. Am. Chem. Soc. 2002, 124,
14820. (b) Leach, A. G.; Houk, K. N. Chem. Commun. 2002,
1243. (c) Leach, A. G.; Houk, K. N. Org. Biomol. Chem.
2003, 1, 1389. (d) Lu, X. Org. Lett. 2004, 6, 2813.
IR (KBr): 2977, 2939, 2872, 1578, 1471, 1386, 1370, 1202, 627
cm–1.
1H NMR (CD2Cl2): d = 2.71 (m, 2 H), 2.38 (m, 1 H), 2.11 (m, 1 H),
1.94 (m, 2 H), 1.34 (s, 6 H), 0.21 (s, 6 H).
Synthesis 2005, No. 20, 3565–3570 © Thieme Stuttgart · New York