SYNTHESIS OF NEW CHIRAL SCHIFF BASES FROM (+)-2-CARENE
37
[α]D21 = +1.85° (c = 1.3, CHCl3). H NMR spectrum, δ,
ppm: 0.51 d.d (2-H, J2,4 = 9.2, J2,1 = 5.1 Hz),
J2,1 = 6.1 Hz), 0.89 d.d.d (4-H, J4,2 = 8.8, J4,5-ax = 8.3,
J4,5-eq = 1.0 Hz), 0.94 s (C9H3), 1.12 s (C10H3), 1.36–
1.47 m (1-H, 6-Hax), 1.58 s (C8H3), 1.66 d.d.d.d (5-Heq,
2J = 15.3, J5-eq,6-ax = 7.5, J5-eq,6-eq = 1.5, J5-eq,4 = 1.0 Hz),
1
0.82 d.d.d (4-H, J4,2 = 9.2, J4,5-ax = 8.2, J4,5-eq
=
1.0 Hz), 1.01 s (C9H3), 1.08 s (C10H3), 1.33 s (C8H3),
2
2
1.29–1.47 m (3H, 6-H, 1-H), 1.57 d.d.d.d (5-Heq, J =
14.8, J5-eq,6-ax = 7.3, J5-eq,4 = 1.0, J5-eq,6-eq = 1.0 Hz),
1.90 d.d.d.d (5-Hax, J = 14.8, J5-ax,6-ax = 11.9, J5-ax,4
8.2, J5-ax,6-eq = 8.2 Hz), 3.54 d.d (11-H, J = 10.3, J11,1
7.2 Hz), 3.77 d.d (11′-H, J = 10.3, J11′,1 = 5.6 Hz),
6.79 d.d.d (17-H, J17,16 = 7.5, J17,18 = 7.5, J17,15
1.1 Hz), 6.78 d.d (15-H, J15,16 = 8.1, J15,17 = 1.1 Hz),
7.19 d.d (18-H, J18,17 = 7.5, J18,16 = 1.6 Hz), 7.24 d.d.d
(16-H, J16,15 = 8.1, J16,17 = 7.5, J16,18 = 1.6 Hz), 8.30 s
(12-H), 14.4 br.s (14-OH). 13C NMR spectrum, δC,
ppm: 44.24 d (C1), 23.05 d (C2), 17.56 s (C3), 19.58 d
(C4), 15.82 t (C5), 38.95 t (C6), 58.75 s (C7), 23.92 q
(C8), 15.77 q (C9), 28.94 q (C10), 64.77 t (C11),
161.16 d (C12), 118.83 s (C13), 162.24 s (C14), 117.49 d
(C15), 132.11 d (C16), 117.84 d (C17), 131.21 d (C18).
Found: m/z 287.1884 [M]+. C18H25O2N. Calculated:
M 287.1880.
1.80 br.d.d (6-Heq, J = 14.3, J6-eq,5-ax = 8.3 Hz),
2
1.91 d.d.d.d (5-Hax, J = 15.3, J5-ax,6-ax = 11.5, J5-ax,4
=
=
2
2
=
=
8.3, J5-ax,6-eq = 8.3 Hz), 3.75 d.d (11-H, J = 11.1, J11,1
2
2
4.7 Hz), 3.93 d.d (11′-H, J = 11.1, J11′,1 = 4.4 Hz),
8.49 d (18-H, J18,16 = 3.1 Hz), 8.58 br.s (12-H), 8.80 d
(16-H, J16,18 = 3.1 Hz), 14.61 br.s (14-OH). 13C NMR
spectrum, δC, ppm: 42.21 d (C1), 21.18 d (C2), 18.05 s
(C3), 18.74 d (C4), 14.79 t (C5), 37.01 t (C6), 60.53 s
(C7), 24.05 q (C8), 15.26 q (C9), 28.29 q (C10), 63.02 t
(C11), 164.06 d (C12), 117.59 s (C13), 170.74 s (C14),
130.68 s (C15), 127.94 d (C16), 140.73 s (C17), 136.74 d
(C18). Found: m/z 377.1579 [M]+. C18H23O6N3. Calcu-
lated: M 377.1581.
2
=
Methyl (1S,2S,3R,6R)-2-(3,5-di-tert-butyl-2-hy-
droxybenzylideneamino)-3,7,7-trimethylbicyclo-
[4.1.0]heptane-3-carboxylate (XVa). A solution of
0.052 g of 3,5-di-tert-butyl-2-hydroxybenzaldehyde
(XIIa) in 5 ml of methanol was added dropwise under
stirring to a solution of 0.052 g of compound VI in
4 ml of anhydrous methanol. The mixture was stirred
for 7 days at room temperature, the solvent was
distilled off, and the residue was purified by column
chromatography on silica gel using hexane–triethyl-
amine (1%)–chloroform (0 to 100%; gradient elution)
as eluent. Yield 0.095 g (100%), [α]D26 = –67.73° (c =
1
Tautomer XIVb. H NMR spectrum, δ, ppm:
0.68 d.d.d (4-H, J4, 2 = 9.2, J4, 5-ax = 7.5, J4, 5-eq
1.0 Hz), 0.81 d.d (2-H, J2,4 = 9.2, J2,1 = 3.8 Hz), 0.96 s
(C9H3), 1.04 s (C10H3), 1.10 m (1-H), 1.19 m (6-Heq),
1.36 s (C8H3), 1.39 m (6-Hax), 1.59 d.d.d.d (5-Heq, 2J =
=
15.0, J5-eq,6-ax = 7.3, J5-eq,6-eq = 1.8, J5-eq,4 = 1.0 Hz),
2
1.78 d.d.d.d (5-Hax, J = 15.0, J5-ax,6-ax = 12.2, J5a,4
=
=
7.5, J5-ax,6-eq = 7.5 Hz), 3.97 d.d (11-H, 2J = 11.4, J11,1
2
1
1.7 Hz), 4.38 d.d (11′-H, J = 11.4, J11′,1 = 2.2 Hz),
5.47 s (12-H), 6.76–6.81 m (15-H, 17-H), 7.14 d.d.d
(16-H, J16, 15 = 8.1, J16, 17 = 7.5, J16, 18 = 1.6 Hz),
7.31 br.d (18-H, J18,17 = 7.5 Hz). 13C NMR spectrum,
δC, ppm: 33.54 d (C1), 22.91 d (C2), 16.89 s (C3),
18.72 d (C4), 14.52 t (C5), 35.98 t (C6), 48.10 s (C7),
24.31 q (C8), 15.42 q (C9), 29.52 q (C10), 69.56 t (C11),
81.26 d (C12), 124.13 s (C13), 155.54 s (C14), 116.52 d
(C15), 129.45 d (C16), 119.07 d (C17), 126.31 d (C18).
0.43, CHCl3). H NMR spectrum, δ, ppm: 0.76 d.d.d
(4-H, J4,2 = 9.4, J4,5-ax = 8.1, J4,5-eq = 2.3), 0.98 d.d
(2-H, J2,4 = 9.4, J2,1 = 5.1 Hz), 1.05 s (C9H3, C10H3),
1.07 m (6-Hax), 1.09 s (C8H3), 1.30 s (16-t-Bu), 1.44 s
(14-t-Bu), 1.47 m (5-Heq), 2.01 m (5-Hax), 2.04 m
(6-Heq), 2.66 d.d (1-H, J1,2 = 5.1 Hz), 3.75 s (OCH3),
7.05 d (17-H, J17,15 = 2.4 Hz), 7.33 d (15-H, J15,17
=
2.4 Hz), 8.27 s (11-H), 13.8 br.s (OH). 13C NMR spec-
trum, δC, ppm: 71.10 d (C1), 27.48 d (C2), 18.00 s (C3),
20.77 d (C4), 16.47 t (C5), 34.64 t (C6), 45.07 s (C7),
24.15 q (C8), 15.56 q (C9), 28.54 q (C10), 165.04 d
(C11), 117.74 s (C12), 158.42 s (C13), 136.72 s (C14),
126.62 d (C15), 139.40 s (C16), 125.63 d (C17), 35.07 s
(C18), 34.06 s (C19), 29.50 q (3C, C20), 31.57 q (3C,
C21), 175.20 s (C22), 51.30 q (C23). Found: m/z
427.3084 [M]+. C27H41NO3. Calculated: M 427.3081.
2-{(1R,2S,3R,6R)-2-Hydroxymethyl-3,7,7-tri-
methylbicyclo[4.1.0]heptan-3-yliminomethyl}-4,6-
dinitrophenol (XIIIc). A solution of 0.099 g of
3,5-dinitrosalicylaldehyde (XIIc) in 5 ml of methanol
was added dropwise under stirring to a solution of
0.121 g of compound XI in 4 ml of anhydrous
methanol. The mixture was stirred for 2 days at room
temperature, the solvent was distilled off, and the
residue was recrystallized from diethyl ether with ad-
dition of hexane. Yield 0.157 g (89%), [α]D21 = +7.5°
Methyl (1S,2S,3R,6R)-2-(2-hydroxybenzylidene-
amino)-3,7,7-trimethylbicyclo[4.1.0]heptane-3-car-
boxylate (XVb). A solution of 0.038 g of 2-hydroxy-
benzaldehyde XIIb in 5 ml of methanol was added to
a solution of 0.104 g of compound VI in 4 ml of anhy-
1
(c = 0.31, CHCl3), mp 60.4°C. H NMR spectrum, δ,
ppm (CDCl3–acetone-d6): 0.80 d.d (2-H, J2,4 = 8.8,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 48 No. 1 2012