Diallylaluminium-N,N-dimethylaminoethanolate, the first stable allyl-alane suitable for additions to aldehydes, ketones and imines

Article abstract of DOI:10.1016/S0040-4039(02)00571-3

The reaction of AlCl₃ with lithium-N,N-dimethylaminoethanolate (3) in a 1:1 ratio yields the corresponding organo-aluminium chloride [Cl₂Al(μ-OCH₂CH₂NMe₂)] ₂ (1) from which the diallyl derivative [(CH₂=CHCH₂)₂Al(μ-OCH₂CH ₂NMe₂)]₂ (4) was synthesized by treatment with 2 equiv. of allyl magnesium bromide. The structures of 1 and 4 were deduced from the ¹H, ¹³C, ²⁷Al NMR spectra and confirmed by X-ray structural determination. The allyl aluminium complex 4 was found to be a useful reagent for the transfer of one allyl group to aldehydes, imines and enones. The 1,2-addition products are formed in high yields.

Full text of DOI:10.1016/S0040-4039(02)00571-3

TETRAHEDRON
LETTERS
Pergamon
Tetrahedron Letters 43 (2002) 3507–3511
Diallylaluminium-N,N-dimethylaminoethanolate, the first stable
allyl-alane suitable for additions to aldehydes,
ketones and imines
a,
a
a
b
Herbert Schumann, * Jens Kaufmann, Sebastian Dechert and Hans-G u¨ nther Schmalz
a
Institut f u¨ r Chemie, Technische Universit a¨ t Berlin, Straße des 17. Juni 135, D-10623 Berlin, Germany
b
Institut f u¨ r Organische Chemie, Universit a¨ t zu K o¨ ln, Greinstraße 4, D-50939 K o¨ ln, Germany
Accepted 21 March 2002
Abstract—The reaction of AlCl with lithium-N,N-dimethylaminoethanolate (3) in a 1:1 ratio yields the corresponding organo-
3
aluminium chloride [Cl Al(m-OCH CH NMe )] (1) from which the diallyl derivative [(CH ꢀCHCH ) Al(m-OCH CH NMe )] (4)
2
2
2
2
2
2
2 2
2
2
2 2
1
13
was synthesized by treatment with 2 equiv. of allyl magnesium bromide. The structures of 1 and 4 were deduced from the H, C,
2
7
Al NMR spectra and confirmed by X-ray structural determination. The allyl aluminium complex 4 was found to be a useful
reagent for the transfer of one allyl group to aldehydes, imines and enones. The 1,2-addition products are formed in high yields.
2002 Elsevier Science Ltd. All rights reserved.
©
5
Although organo-aluminium compounds have found a
wide-spread use in organic synthesis, only a few allyl
and its application in organic synthesis. In this paper the
1
synthesis, spectroscopic investigation and characteriza-
tion of the allyl analogue and its use in organic synthesis
will be reported.
derivatives have been investigated and found applica-
2
tion. The etherates of allyl-, methallyl-, and crotyl-alu-
minium compounds seem to be stable at room
temperature, but owing to the high auto reactivity of
3
Previously we reported the synthesis of the dimeric
such allylic alanes so far only one pure compound has
dichloroaluminium
alkoxide
[Cl Al(m-OCH CH
2
2
2-
1
been isolated and characterized by
spectroscopy.
H
NMR
NMe2)]2 (1) via abstraction of HCl by reacting
4
equivalent amounts of AlCl with Me NCH CH OH
3
2
2
2
5
6
(
2). Via an alternative route pure 1 can be isolated by
In the framework of our studies on intramolecularly
stabilized organo-aluminium compounds, we recently
reported the synthesis of a vinyl-aluminium compound
reacting the lithium-alcoholate (3) with equimolar
amounts of AlCl (Scheme 1). Recrystallization of the
7
3
crude product from THF yielded colorless crystals of 1.
O
Cl
Cl
a
b
AlCl3
HO
N
LiO
N
Al
N
2
2
3
1
Scheme 1. (a) To a solution of Me NCH CH OH (2) (6.24 g, 70.11 mmol) in n-hexane (50 mL) was added n-BuLi (44 mL, 70.11
2
2
2
mmol, 1.6 M) in n-hexane at 0°C. The mixture was stirred for 12 h at room temperature and the solvent was removed under
reduced pressure. The crude product was recrystallized from hexane. Yield: 5.5 g (84%) of 3. (b) To a solution of AlCl (3.99 g,
3
29.9 mmol) in diethyl ether (50 mL) at 0°C was added 3 (2.84 g, 29.9 mmol) in diethyl ether (50 mL) at −78°C. The mixture was
stirred for 12 h at 20°C, the solvent was decanted, and the crude product was recrystallized from THF. Yield: 4.00 g (74%) of
pure 1.
Keywords: addition reaction; aldehydes; allyl complexes; aluminium; imines.
*
Corresponding author. Tel.: +49-30-31423984; fax: +49-30-31422168; e-mail: schumann@chem.tu-berlin.de
0
040-4039/02/$ - see front matter © 2002 Elsevier Science Ltd. All rights reserved.
PII: S0040-4039(02)00571-3

3
508
H. Schumann et al. / Tetrahedron Letters 43 (2002) 3507–3511
Scheme 2. CH ꢀCHCH MgCl (12.7 mL, 1.63 M) in THF was added to 1 (1.91 g, 10.32 mmol) in THF (60 mL) at −78°C. The
2
2
solution was stirred for 12 h at 0°C, the solvent was removed under vacuum, and the residue was washed with n-hexane (70 mL).
Filtration and concentration of the organic phase yielded, after recrystallization from hexane, pure 4 (1.44 g, 71%).
8
Figure 1. ORTEP diagram of the structure of [Cl Al(m-OCH CH NMe )] (1). Thermal ellipsoids are shown at the 50%
2
2
2
2 2
probability level. Hydrogen atoms are omitted for clarity. Selected bond lengths (A) and angles (°): AlꢁO 1.8403(19), AlꢁO%
,
1
.8632(19), Al–N 2.066(2), Al–Cl(1) 2.1661(10), AlꢁCl(2) 2.1833(10); NꢁAlꢁO% 152.94(9), OꢁAlꢁO% 75.39(9), OꢁAlꢁN 81.43(9),
OꢁAlꢁCl(1) 111.31(7), OꢁAlꢁCl(2) 138.58(7), O%ꢁAlꢁCl(1) 100.72(7), O%ꢁAlꢁCl(2) 95.17(7), Cl(1)ꢁAlꢁCl(2) 110.06(4), Cl(1)ꢁAlꢁN
1
00.58(7), Cl(2)ꢁAlꢁN 93.02(7). Symmetry transformation used to generate equivalent atoms: (%) −x+1, −y+1, −z+1.
8
Figure 2. ORTEP diagram of the structure of [(CH ꢀCHCH ) Al(m-OCH CH NMe )] (4). Thermal ellipsoids are shown at the
2
2 2
2
2
2 2
3
0% probability level. Hydrogen atoms are omitted for clarity. Selected bond lengths (A
.9426(15), Al–N 2.2026(18), Al–C(1) 2.010(2), Al–C(4) 2.014(2), C(1)–C(2) 1.471(4), C(2)–C(3) 1.303(4), C(4)–C(5) 1.462(3),
,
) and angles (°): Al–O 1.8390(16), Al–O%
1
C(5)–C(6) 1.327(4); N–Al–O% 153.85(8), O–Al–O% 74.24(7), O–Al–N 79.72(7), O–Al–C(1) 118.69(9), O–Al–C(4) 127.28(10),
O%–Al–C(1) 95.74(9), O%–Al–C(4) 97.31(8), C(1)–Al–C(4) 113.87(11), C(1)–Al–N 98.80(9), C(4)–Al–N 96.50(8). Symmetry transfor-
mation used to generate equivalent atoms: (%) −x+1, −y+1, −z+1.

H. Schumann et al. / Tetrahedron Letters 43 (2002) 3507–3511
3509
Table 1. Allyltransfer studies on 1,2- and 1,4-addition of [(CH ꢀCHCH ) Al(m-OCH CH NMe )] (4) to various enones,
2
2 2
2
2
2 2
aldehydes and imines
a
Isolated yields.
b
0
.45 g (2.69 mmol) of 4 is solved in toluene (5 mL), added drop-wise to a solution of 0.29 g (2.96 mmol) in 5a in toluene (5 mL) heated to 100°C
for 12 h, and quenched with aqueous NaCl (20 mL) and HCl (10%, 2 mL). Extraction with CH Cl (30 mL), dried over Na SO4 and
2
2
2
concentrated, followed by purification by column chromatography (hexane/ethyl acetate 20/1). Yield: 0.37 g (93%) of 9a.
c
d
e
f
0
.2 g (1.01 mmol) of 4, 0.19 g (1.01 mmol) of 6b. Yield: 0.22 g (95%) of 9b.
.94 g (4.76 mmol) of 4, 0.89 g (4.76 mmol) of 7. Yield: 0.98 g (90%) of 10.
.18 g (1.0 mmol) of 4, 0.21 g (1.0 mmol) of 8. Yield: 0.07 g of 11a and 0.15 g of 11b (87%).
.11 g (0.65 mmol) of 4 is solved in toluene (5 mL). 0.14 g (0.65 mmol) of trans-chalcone 8 in toluene (5 mL) and 10 mol% of Ni(acac)2 are
added, stirring for 12 h at 22°C. Yield: 0.15 g (91%) of 11b.
0
0
0
N,N-Dimethylaminoethanolatoaluminium
dichloride
after a couple of days storage under nitrogen no
decomposition was observed.
(
1) reacts with 2 equiv. of allyl magnesium bromide to
form the new diallyl-aluminum complex [(CH ꢀ
CHCH ) Al(m-OCH CH NMe )] (4) via salt elimina-
2
9
Crystals of 1 (Fig. 1) and 4 (Fig. 2) suitable for
2
2
2
2
2 2
10
tion (Scheme 2). Compound 4 could be isolated as
colorless crystals from its n-hexane solution. The com-
pound proved to be stable at room temperature. Even
single-crystal X-ray analysis were obtained from THF
and n-hexane solution at −28°C. Compounds 1 and 4
are oxygen-bridged dimeric molecules with inversion

3
510
H. Schumann et al. / Tetrahedron Letters 43 (2002) 3507–3511
symmetry in the solid state. In both compounds, the
aluminium atoms are five-coordinated with a distorted
trigonal bipyramidal geometry. The nitrogen and one
oxygen atom are in the axial positions, whereas the
bridging oxygen and two chlorine atoms (1) or the
bridging oxygen and two carbon atoms of the allylic
groups (4) occupy the equatorial positions. The
Aust. J. Chem. 1975, 28, 817; (c) Ashby, E. C.; Heisohn,
G. J. Org. Chem. 1974, 39, 3297; (d) Baidossi, W.;
Rosenfeld, A.; Wassermann, B. C.; Schutte, S.; Schu-
mann, H.; Blum, J. Synthesis 1996, 9, 1127; (e) Kunz, H.;
Pees, K. J. J. Chem. Soc., Perkin Trans. 2 1989, 1168; (f)
Sato, F.; Oikawa, T.; Sato, M. Chem. Lett. Chem. Soc.
Jpn. 1979, 167; (g) Corey, E. J.; Varma, R. K. J. Am.
Chem. Soc. 1971, 29, 7320; (h) Schwartz, J.; Carr, D. B.;
Hansen, R. T.; Dayrit, F. M. J. Org. Chem. 1980, 45,
3053.
AlꢁO
(1.94 A
,
), AlꢁO
(1.84 A
,
) and AlꢁN bond
) and the NꢁAlꢁO% angle (153.9°) in 4
are in close accordance with the values recently
reported for the analogous vinylalane (AlꢁO 1.92 A
axial
equat.
lengths (2.20 A
,
,
;
2. (a) Eisch, J. J.; Mackenzie, K.; Windisch, H.; Kr u¨ ger, K.
Eur. J. Inorg. Chem. 1999, 153; (b) Minowa, N.;
Mukaiyama, T. Bull. Chem. Soc. Jpn. 1987, 60, 3697; (c)
Mukaiyama, T.; Minowa, N.; Oriyama, T.; Narasaka, K.
Chem. Lett. 1986, 97; (d) Zhang, Y.; Negishi, E. J. Am.
Chem. Chem. Soc. 1989, 111, 3454; (e) You, J.-S.; Hsieh,
S.-H.; Gau, H.-M. Chem. Commun. 2001, 1546.
axial
5
AlꢁO
1.84 A
,
; NꢁAlꢁO% 153.1°). The electron-with-
drawing effect of the chlorine is responsible for the
decrease of the Al–N (2.07 A) and AlꢁO (1.86 A
distances in 1, but does not affect the AlꢁO
equat.
,
,
)
axial
equat.
(1.84
,
) distance, which is similar to that in 4 and close to
A
11
values found for other dimethylaminoalkoxides.
3
. Lehmkuhl, H.; Reinehr, D. J. Organomet. Chem. 1970,
In order to test the use of compound 4 in organic
23, C25.
synthesis, a variety of aldehydes, imines, and enones
4. Stefani, A.; Pino, P. Helv. Chim. Acta 1972, 55, 1110.
5. Schumann, H.; Kaufmann, J.; Dechert, S.; Schmalz, H.-
G.; Velder, J. Tetrahedron Lett. 2001, 42, 5405.
12
were reacted with the allyl-alane (Table 1). In a
standard procedure, a solution of the substrate in tolu-
ene was treated with 4. The mixture was stirred for 12
h at 100°C, and after a standard workup in the case of
benzaldehyde 5a, para-bromo-benzaldehyde 6b (entries
1
6. Spectral data for 1: H NMR (d-pyridin): l 2.47 (s, 6H,
NCH ), 2.83 (t, 1H, J=6.06 Hz, NCH ), 4.05 (t, 2H,
3
2
1
3
J=6.06 Hz, OCH ). C NMR (d-pyridin): l 33.12,
52.12, 58.77. Al NMR: 58.20 Hz. Mp 248.5–249.0°C
(dec.). Anal. calcd for C H Al Cl N O : C, 25.83; H,
2
27
1
and 2) and benzylidene-cyclohexyl-amine 7 (entry 3),
13
14
15
the 1,2-addition products 9a, 9b and 10 were iso-
lated in high yields. Treatment of 1,3-diphenyl-2-
propene-1-one PhCHꢀCHCOPh (trans-chalcone) (8)
8
20
2
4
2
2
5.42. Found C, 25.61; H, 6.11%. MS: m/z (%): 371.9 (1)
+
[M] , 337.1 (11), 72.1 (18), 77.2 (23), 58.1 (100).
16
with alane 4 at 100°C yields a mixture of 1,4- (11a)
7. All reactions were carried out in an atmosphere of dry,
oxygen-free nitrogen using Schlenk techniques. Solvents
were dried over sodium, purified and saturated with
nitrogen prior to use. Elemental analyses were performed
on a Perkin–Elmer 240 C elemental analyser. Mass spec-
tra (electron impact ionisation) were obtained on a
Varian MAT 311 A instrument (70 eV). NMR spectra
17
and 1,2-adduct (11b) in a 1:3 ratio (entry 4). The
regioselectivity of the transfer improved under milder
conditions upon addition of 10 mol% Ni(acac) -cata-
2
lyst. The reaction was stirred at room temperature for
12 h and solely 1,2-adduct isolated (entry 5).
1
In summary, N,N-dimethylaminoethanolatoaluminium
dichloride (1) is an excellent starting material for the
synthesis of intramolecularly stabilized organo-alu-
minium compounds with allylic ligands. It enables the
synthesis of the first stable allyl-aluminium compound
were recorded on a Bruker ARX 200 spectrometer ( H
NMR at 200 MHz; C{ H} NMR at 50.32 MHz) unless
stated otherwise.
13
1
8. Zsolnai, L.; Pritzkow, H. ZORTEP ORTEP Program for
PC; Universit a¨ t Heidelberg, 1994.
9. Spectral data for 4: H NMR (C D ): l 1.19 (d, 8H,
1
4
, which has been characterized by X-ray structure
6
6
analysis, via salt elimination. This new type of alu-
minium reagent shows high potentials in organic syn-
thesis, as demonstrated in the transfer of the allyl group
to a selection of aldehydes, carbonyles, and imines via a
J=8.67 Hz, AlCH ) 1.87 (s, 6H, NCH ), 1.95 (t, 2H,
J=5.88 Hz, NCH ), 3.48 (t, 2H, J=5.88 Hz, OCH ),
2
3
2
2
4.75–4.82 (m, 1H, CHꢀCHH%), 4.89–4.91 (m, 1H,
13
CHꢀCHH%), 6.22–6.35 (m, 1H, CHꢀCHH%). C NMR
2
7
1,2-addition.
(C D ): l 20.18, 44.77, 56.96, 59.01, 105.34, 143.93. Al
6 6
NMR: 89.23 Hz. Mp 100.2–101.6°C. Anal. calcd for
C H Al N O : C, 60.89; H, 10.22. Found C, 60.12; H,
2
0
40
2
2
2
+
Acknowledgements
10.36%. MS: m/z (%): 353.1 (14) [M−C H ] , 156.0 (28),
3 5
72.1 (100), 42.0 (32).
10. X-Ray structure determination. Data were collected on a
We thank the Fonds der Chemischen Industrie and the
Deutsche Forschungsgemeinschaft (Graduiertenkolleg
Siemens SMART CCD diffractometer (graphite
monochromated Mo Ka radiation, u=0.71073 A) with
,
‘
Synthetische, mechanistische und reaktionstechnische
Aspekte von Metallkatalysatoren’) for support of this
area-detector at 173 K. The structures were solved by
2
direct methods and refined on F using all reflections with
work.
the SHELX-97 software package [Sheldrick, G. M.
SHELX-97 Program for Crystal Structure Determina-
tion, Universit a¨ t G o¨ ttingen, G o¨ ttingen, Germany, 1997].
All non-hydrogen atoms were refined anisotropically. The
References
hydrogen atoms were placed in calculated positions and
2
1. (a) Bagnell, L.; Meisters, A.; Mole, T. Aust. J. Chem.
assigned an isotropic displacement parameter of 0.08 A
,
.
1
975, 28, 363; (b) Bagnell, L.; Meisters, A.; Mole, T.
SADABS [Sheldrick, G. M. SADABS Empirical Absorp-

H. Schumann et al. / Tetrahedron Letters 43 (2002) 3507–3511
3511
1
3
tion Correction Program, Universit a¨ t G o¨ ttingen, G o¨ ttin-
gen, Germany, 1996.] was used to perform area-detector
scaling and absorption corrections (1: Tmax=0.9197,
Tmin=0.4573; 4: Tmax=0.9640, Tmin=0.4536). Crystal
data for C H Al Cl N O (1): fw=372.02, crystal
(m, 4H, Carom.). C NMR (CDCl ): l 43.5, 73.2, 117.9,
3
−
1
125.7, 127.3, 128.3, 134.4, 143.8. IR (cm ): 3367 (s), 3030
(m), 1895 (s), 1494 (m), 1107 (m), 757 (s). MS: m/z (%):
148.0 (1) [M] , 107.0 (100), 77.2 (23), 77.0 (36), 40.9 (6).
+
14. Spectral data for 1,2-addition product 9b (C H BrO):
8
20
2
4
2
2
10 11
1
dimensions 0.52×0.14×0.19 mm, monoclinic, space group
H NMR (CDCl ): l 2.23 (s, br, 1H, OH), 2.46 (m, 2H,
3
P2 /n, a=6.9432(1), b=10.2031(2), c=11.9044(3) A
,
, i=
CH ), 4.69 (dd, 1H, J=5.6, 7.3 Hz, OCH), 5.11–5.13 (m,
1
2
3
3
9
2.822(1)°, V=842.31(3) A
,
, Z=2, zcalcd=1.467×10 kg
1H, CHꢀCHH%), 5.18–5.20 (m, 1H, CHꢀCHH%), 5.67–
5.84 (m, 1H, CHꢀCHH%), 7.19–7.25 (m, 2H, Carom.),
−
3
−1
m , v=0.802 mm , F(000)=384, 5.26°52q555.0°,
75h59, −135k511, −145l515, 6289 data col-
lected, 1926 unique data (Rint=0.0824), 1404 data with
1
3
−
7.44–7.49 (m, 2H, Carom.). C NMR (CDCl ): l 43.6,
3
−
1
72.5, 118.7, 121.2, 127.5, 131.4, 133.9, 142.8. IR (cm ):
3388 (s), 2978 (m), 1895 (s), 1639 (m), 1580 (m), 1070 (s),
870 (s). MS: m/z (%): 227.0 (1) [M] , 186.9 (72), 156.9
2
I>2|(I), 84 refined parameters, GOF (F )=1.001, final R
2
o
2 2
c
+
indices
(R =SꢀF ꢁ−ꢁF ꢀ/SꢁF ꢁ,
wR =[Sw(F −F ) /
1
o
c
o
2
2
2 1/2
Sw(F ) ] ) R =0.0449, wR =0.0942, max./min. resid-
(26), 77.0 (100), 40.9 (12).
15. Spectral data for 1,2-addition product 10 (C H N): H
o
1
2
−
3
1
ual electron density 0.400/−0.455 e A
,
. Crystal data for
16
23
C H Al N O (4): fw=394.50, crystal dimensions 0.36×
NMR (CDCl , 500 MHz): l 1.15 (m, 4H, CH ), 1.58 (m,
20
40
2
2
2
3
2
0
.45×0.66 mm, triclinic, space group P-1, a=7.6631(4),
b=7.7609(4), c=10.7628(5) h=96.895(2), i=
8.853(1), k=107.717(1)°, V=592.92(5)
4H, CH
2
), 1.98 (m, 4H, CH
2
), 2.27 (m, 2H, CH ), 2.37
2
A
,
,
(m, 1H, CH), 1.35 (s, 1H, NH), 3.87 (t, 1H, J=6.42 Hz,
NCHC ), 5.02–5.15 (m, 2H, CHꢀCHH%), 5.73 (m, 1H,
CHꢀCHH%), 7.23–7.34 (m, 5H,
(CDCl ): l 24.68, 25.00, 25.99, 32.77, 34.58, 43.37, 56.06,
58.81, 117.09, 126.42, 126.85, 128.14, 135.48, 144.60. IR
3
9
A
,
,
Z=1,
H
6 5
3
−3
−1
13
zcalcd=1.105×10 kg m , v=0.138 mm , F(000)=216,
C
arom.).
C NMR
3
4
1
.90°52q555.0°, −95h59, −65k510, −135l513,
529 data collected, 2686 unique data (Rint=0.0489),
3
−
1
919 data with I>2|(I), 120 refined parameters, GOF
(cm ): 3427 (m), 2853 (s), 1451 (m), 759 (s). MS: m/z
2
+
(
F )=1.001, final R indices (R =SꢀF ꢁ−ꢁF ꢀ/SꢁF ꢁ, wR =
(%): 228.0 (1) [M] , 188.0 (100), 131.0 (3), 105.9 (56), 79.0
(15), 40.9 (11).
1
o
c
o
2
2
o
2 2
c
2 2 1/2
[
Sw(F −F ) /Sw(F ) ]
)
R =0.0588, wR =0.1374,
o
1
2
−
3
1
max./min. residual electron density 0.400/−0.455 e A
,
.
16. Spectral data for 1,2-addition product 11b (C18
NMR (CDCl
(m, 2H, CH
CHꢀCHH%), 6.54 (d, 1H, J=16.0 Hz, C
6.67 (d, 1H, J=16.0 Hz, C CHꢀCH), 7.23–7.40 (m,
8H, Carom.), 7.52–7.54 (m, 2H, Carom.).
(CDCl ): l 47.2, 75.7, 118.7, 120.3, 125.5, 126.6, 127.1,
H
18O): H
Crystallographic data (excluding structure factors) for the
structures reported in this paper have been deposited with
the Cambridge Crystallographic Data Centre as supple-
mentary publications no CCDC-178877 (1) and CCDC-
3
, 500 MHz): l 2.33 (s, br, 1H, OH), 2.82
), 5.21 (m, 2H, CHꢀCHH%), 5.74 (m, 1H,
CHꢀCH),
2
H
5
6
H
6
5
13
1
78878 (4). Copies of the data can be obtained free of
C NMR
charge on application to CCDC, 12 Union Road, Cam-
bridge CB2 1EZ, UK (fax: (+44) 1223-336-033; e-mail:
deposit@ccdc.cam.ac.uk).
3
−
1
127.7, 128.4, 133.2, 135.3, 136.8, 145.3. IR (cm ): 3555
(s), 3080 (m), 2978 (m), 1753 (s), 1345 (m), 1030 (m), 844
(s). MS: m/z (%): 250.0 (1) [M] , 209.0 (100), 130.9 (53),
+
1
1. Francis, J. A.; McMahon, C. N.; Bott, S. G.; Barron, A.
R. Organometallics 1999, 18, 4399.
115 (9), 77.0 (40), 40.9 (7).
1
1
2. Reagents for addition reactions were bought from
Aldrich. Imine 6 was synthesized according to the litera-
ture [Parry, K. A. W. J. Chem. Soc. B 1970, 700]. The
addition products were isolated as racemic mixtures. First
evidence shows that the stereochemistry in the products
can be controlled using chiral auxiliaries.
17. Spectral data for 1,4-addition product 11a (C18
NMR (CDCl ): l 2.45 (m, 2H, CH
2H, CH ), 3.50 (m, 1H, CH), 5.00 (m, 2H, CHꢀCHH%),
5.71 (m, 1H, CHꢀCHH%), 7.19–7.30 (m, 4H, Carom.),
H
18O): H
CHꢀCHH%), 3.32 (m,
2
3
2
13
7.44–7.55 (m, 4H, Carom.) 7.89–7.94 (m, 2H, Carom.).
NMR (CDCl ): l 40.6, 40.7, 44.5, 116.8, 126.3, 127.5,
128.0, 128.4, 128.5, 132.9, 136.3, 137.2, 144.3, 198.9. IR
C
3
1
1
3. Spectral data for 1,2-addition product 9a (C H O): H
10
12
−
1
NMR (CDCl ): l 2.59 (m, 2H, CH ), 2.79 (s, br, 1H,
OH), 4.77 (t, 1H, J=6.4 Hz, OCH), 5.18–5.27 (m, 2H,
CHꢀCHH%), 5.79–5.97 (m, 1H, CHꢀCHH%), 7.41–7.45
(cm ): 3422 (w), 3062 (w), 1686 (s), 1494 (s), 1202 (m),
3
2
+
1002 (s), 846 (s). MS: m/z (%): 250.0 (7) [M] , 129.0 (7),
104.9 (100), 77.0 (40).