Highly branched alkanoic acids from the preen-gland wax of the domestic goose as building blocks for chiral triphenylenes

Article abstract of DOI:10.1002/1522-2675(200211)85:11<3909::AID-HLCA3909>3.0.CO;2-R

The synthesis of chiral triphenylenes 7a,b bearing side chains derived from enantiomerically pure trimethyloctanoate 1a and tetramethyldecanoate 1b from the preen-gland wax of domestic goose was achieved in 3 or 4 steps. Compounds 7a,b were nonmesogenic;

Full text of DOI:10.1002/1522-2675(200211)85:11<3909::AID-HLCA3909>3.0.CO;2-R

Helvetica Chimica Acta Vol. 85 (2002)
3909
Highly Branched Alkanoic Acids from the Preen-Gland Wax of the
Domestic Goose as Building Blocks for Chiral Triphenylenes
by Andreas Schultza), Sabine Laschat*a)1), Michael Morrb), Siegmar Dielec), Michael Dreyerd),
and Gerhard Bringmannd)
a) Institut f¸r Organische Chemie, Technische Universit‰t Braunschweig, Hagenring 30, D-38106 Braunschweig
(fax: ‡49-(0)531-3915388; e-mail: s.laschat@tu-bs.de)
b) Gesellschaft f¸r Biotechnologische Forschung, Mascheroder Weg 1, D-38124 Braunschweig
(fax: ‡49-(0)531-6181795; e-mail: mmo@gbf.de)
c) Institut f¸r Physikalische Chemie, Martin-Luther Universit‰t Halle-Wittenberg, M¸hlpforte 1, D-06108 Halle
(e-mail: diele@chemie.uni-halle.de)
d) Institut f¸r Organische Chemie, Universit‰t W¸rzburg, Am Hubland, D-97074 W¸rzburg
(fax: ‡49-(0)931-8884755; e-mail: bringman@chemie.uni-wuerzburg.de)
Dedicated to Professor Dieter Seebach on the occasion of his 65th birthday
The synthesis of chiral triphenylenes 7a,b bearing side chains derived from enantiomerically pure
trimethyloctanoate 1a and tetramethyldecanoate 1b from the preen-gland wax of domestic goose was achieved
in 3or 4 steps. Compounds 7a,b were nonmesogenic; however, mixtures of 7a,b with hexakis(octyloxy)tri-
phenylene or hexakis(decyloxy)triphenylene displayed columnar mesophases or soft crystal G phases, as was
shown by differential-scanning calorimetry and optical-polarizing microscopy. Circular-dichroism measure-
ments revealed weak associations of 7a,b in solution.
Introduction. Hexakis(alkyloxy)-substituted triphenylenes are important building
blocks for thermotropic columnar liquid crystals [1 3]. As a result of their short-range
ordered assembly in the mesophase, several members of this family display high charge-
carrier mobilities along the columns, as well as high electrical conductivity and
photoconductivity, which make these compounds promising candidates for applications
[4][5]. In addition, even in solution, hexakis(alkyloxy)triphenylenes can undergo self-
assembly, form charge-transfer complexes with strong electron acceptors [6], or give
helical structures with chiral intercalating agents [7]. In contrast, the chemistry and
properties of chiral triphenylenes have been used to a much smaller extent [6b][8].
This is probably due to the fact that a convenient access to chiral side-chain precursors
is required. It has recently been shown that the preen-gland wax of domestic goose
contains large amounts of (2R,4R,6R,8R)-2,4,6,8-tetramethyldecanoates and related
highly methylated alkanoic acids, which can conveniently be isolated on a gram-scale
¾
employing transesterification and Spaltrohr distillation [9]. Furthermore, it was
demonstrated that these alkanoic acids can be used for calamitic liquid crystals giving
broader SmC* phases than the corresponding derivatives with a single methyl
branching [10]. We were, thus, interested whether such alkanoic acids can be used for
1
)
New address: Institut f¸r Organische Chemie, Universit‰t Stuttgart, Pfaffenwaldring 55, D-70569
Stuttgart.

3910
Helvetica Chimica Acta Vol. 85 (2002)
the preparation of chiral triphenylenes as well. The results concerning synthesis and
properties are reported below.
Results and Discussion. The synthesis of chiral triphenylenes 7a,b is outlined in
the Scheme. Starting from enantiomerically pure methyl (2R,4R,6R)-2,4,6-trimethyl-
octanoate (1a), reduction with LiAlH4 yielded alcohol 2a in 96% yield [9]. Reduction
of the corresponding methyl (2R,4R,6R,8R)-2,4,6,8-tetramethyldecanoate (1b) gave
alcohol 2b almost quantitatively. Reaction of 2a and 2b with Br2 in the presence of PPh3
provided the bromides 3a and 3b in 92 and 96% yield, respectively. Subsequent
alkylation of catechol (4) with bromides 3a and 3b in the presence of K2CO3 in DMF
gave the chiral 1,2-bis(alkyloxy)benzenes 5a and 5b in 62 and 67% yield, respectively.
Compounds 5a,b turned out to be highly volatile and, therefore, precautions had to be
taken during workup and evaporation of solvents. Oxidative trimerization of 1,2-
bis(alkyloxy)benzenes 5a,b was achieved in the presence of 1 equiv. of MoCl5 in
CH2Cl2 at room temperature [11] yielding the desired triphenylenes 7a,b in 19 and 44%
(Method A). As an alternative route, direct alkylation of triphenylenehexal 6 [12] with
bromides 3a,b in the presence of 20 equiv. of K2CO3 in DMF at 1008 was attempted
(Method B); to our delight the yield of compound 7a could be improved (47%), and
compound 7b was obtained in 45%.
Differential-scanning calorimetry (DSC) and optical-polarizing microscopy re-
vealed no mesomorphic properties of 7a,b. Both compounds were colorless isotropic
oils at room temperature. During the first cooling cycle, triphenylene 7a showed a
melting transition from the isotropic liquid to the crystalline phase at À368 and a
crystal-to-crystal transition at À1328. The corresponding transition temperatures for
compound 7b were observed at À37 and À1348. Comparison with the known chiral
hexakis{[(3R)-3,7-dimethyloctyl]oxy}triphenylene derived from (3R)-dihydrocitronel-
lol, which displays a disordered hexagonal columnar mesophase between 19 and 368
[8a], indicates that the introduction of additional branching points in the side chain
severely damages mesophase stability.
Next, mixtures of chiral triphenylenes 7a and 7b with hexakis(octyloxy)tripheny-
lene (HAT8) [13] and hexakis(decyloxy)triphenylene (HAT10) [13], respectively,
were studied by DSC and optical-polarizing microscopy. The results are summarized in
the Table. Whereas HAT8 displays a hexagonal columnar mesophase between 67 and
878 (Entry 1), admixture of the chiral triphenylene 7a and HAT8 resulted in an overall
decrease of the phase-transition temperatures and a change of the phase behavior in
most cases (Entries 2 13). For the 10 :1 mixture HAT8/7a, only a melting transition
was obtained by DSC (Entries 2 4). However, on cooling from the isotropic phase, a
mosaic texture with star-shaped domains typical of a soft crystal G phase (formerly
assigned as SmG) [14][15] was detected under the microscope between 59 and 478
(Fig. 1). Upon further cooling to room temperature, the mixture crystallized. The 5 :1
mixture HAT8/7a displayed a crystal-to-crystal transition at 458 and a melting
transition at 628 during first heating (Entry 5). Further cooling/heating cycles revealed
only one phase transition (Entries 6 and 7). DSC Results were supported by optical
investigations. In contrast, the 2 :1 mixture displayed monotropic mesomorphic
behavior. A melting transition was detected at 468 and a clearing transition at 588
(Entry 8). During subsequent heating cycles, similar transition temperatures were

Helvetica Chimica Acta Vol. 85 (2002)
3911
Scheme
found (Entries 9 and 10). Optical investigations revealed a columnar texture with
spherulitic domains upon rapid cooling between 48 and 588 (Fig. 2). The 1:1 mixture
displayed enantiotropic melting behavior (Entries 11 13). Under the microscope, fan-
shaped textures typical of columnar mesophases were detected at 638 upon cooling.
HAT10 displays a hexagonal columnar mesophase between 58 and 698 (Entry 15).
Addition of 7b to HAT10 again resulted in a dramatic change of the phase behavior.
For all three mixtures (10 :1, 5 :1, and 2 :1), a crystal-to-crystal transition and a melting
transition can be observed on first heating (Entries 16, 19, and 22). Subsequent cooling
cycles lead immediately to crystallization. Under the microscope, crystalline fibres
were detected. However, a 1:1 contact preparation of HAT10 and 7b yielded a fan-

3912
Helvetica Chimica Acta Vol. 85 (2002)
Table. Phase-Transition Temperatures and Enthalpies of Chiral Triphenylenes 7a,b and Mixtures with Achiral Triphenylenes
HAT8 or HAT10a)
Entry Compound(s) Ratio Temp. Cycle
Phase Ib) Ttrans1 [8]
(DHtrans1 [kJ molÀ1])
Phase IIb) Ttrans2 [8]
(DHtrans2 [kJ molÀ1])
Phase IIIb)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
HAT8
1st heatingc)
K
K
67
Colh
I
Gcr
I
K2
K1
I
Col
K
Col
Col
Col
Col
K2
Colh
K2
K1
I
87
I
HAT8/7a
HAT8/7a
HAT8/7a
HAT8/7a
HAT8/7a
HAT8/7a
HAT8/7a
HAT8/7a
HAT8/7a
HAT8/7a
HAT8/7a
HAT8/7a
7a
10 : 1 1st heating
56 (62.5)
44 (59.1)
64 (79.4)
45 (6.7)
42 (56.9)
54 (60.9)
46 (0.8)
37 (58.4)
48 (54.1)
47
10 : 1 1st coolinga)d) I
10 : 1 2nd heating
5 : 1 1st heating
5 : 1 1st cooling
5 : 1 2nd heating
2 : 1 1st heating
2 : 1 1st cooling
2 : 1 2nd heating
1 : 1 1st heatingd)
1 : 1 1st coolingd)
1 : 1 2nd heatingd)
1st heating
K
K1
I
K1
K
I
K
K
I
K
K1
K
K1
I
K1
K1
I
K1
K1
I
K1
K
I
62 (64.8)
58 (65.1)
I
I
58 (2.1)
67
51
60
I
I
K
I
I
66
47
À 132 (38.0)
À 36 (5.2)
HAT10
1st heatingc)
58
69
I
I
HAT10/7b
HAT10/7b
HAT10/7b
HAT10/7b
HAT10/7b
HAT10/7b
HAT10/7b
HAT10/7b
HAT10/7b
HAT10/7b
HAT10/7b
HAT10/7b
7b
10 : 1 1st heating
10 : 1 1st cooling
10 : 1 2nd heating
5 : 1 1st heating
5 : 1 1st cooling
5 : 1 2nd heating
2 : 1 1st heating
2 : 1 1st cooling
2 : 1 2nd heating
1 : 1 1st heatingd)
1 : 1 1st coolingd)
1 : 1 2nd heatingd)
1st heating
54 (11.9)
46 (73.5)
57 (76.1)
53(32.7)
45 (72.0)
56 (75.5)
44 (88.2)
41 (72.7)
53(73.3)
48
58 (81.1)
K
57 (84.4)
52 (93.3)
I
I
2
K1
I
K2
K1
I
Col
Col
Col
K2
72
42
71
I
K
I
66
47
K
K1
À 134 (23.4)
À 37 (6.6)
I
a) Transition temperatures were determined by DSC (heating rate 10 K minÀ1). b) The following phases were observed: K
(crystalline), Colh (hexagonal columnar), Gcr (soft crystalline G phase), and I (isotropic). c) See [14]. d) Transition
temperatures were determined by optical-polarizing microscopy.
shaped texture between 48 and 728 on heating (between 66 and 428 on cooling)
(Entries 25 27). The texture was assigned to a hexagonal columnar mesophase.
Thus, it seems that with increasing concentration of the chiral triphenylene 7a,b,
stable mesophases can be obtained. Unfortunately, further confirmation of these
assignments by X-ray diffraction were not possible.
Next, CD spectra of solutions of chiral triphenylenes 7a,b in CHCl3 and hexane
were examined (Figs. 3 and 4). The spectra in CHCl3 differ from those in hexane. In
particular, the ellipticity of 7a increases in hexane as compared to CHCl3. The same
result was found for 7b. Noteworthy are the sharp and relatively intense peaks at ca.
277 nm for both 7a and 7b in hexane, showing opposite signs. The reason for this
remains to be investigated. The solvent-dependence of the circular dichroism is
probably caused by an increased association of the triphenylene moieties in the
nonpolar solvent resulting from p-p stacking interactions [7]. The fact that the
observed ellipticities were relatively small may be either due to weak aggregation or

Helvetica Chimica Acta Vol. 85 (2002)
3913
Fig. 1. Mosaic texture with star-shaped domains of HAT8/7a 10 :1. The photomicroscopic image of the mesophase
was obtained at 508 on cooling (28 minÀ1) from the isotropic liquid (crossed polarizers, magnification Â100)
Fig. 2. Columnar texture with spherulitic domains of HAT8/7a 2 :1. The photomicroscopic image of the
mesophase was obtained at 518 on cooling (108 minÀ1) from the isotropic liquid (crossed polarizers,
magnification Â100).

3914
Helvetica Chimica Acta Vol. 85 (2002)
Fig. 3. CD Spectrum of triphenylene 7a in CHCl3 (c ˆ 10À3 mol lÀ1) (left) and in hexane (c ˆ 10À3 mol lÀ1) (right).
The grey area indicates the range of wavelength where no significant measurement is possible due to the
absorption of the solvent.
Fig. 4. CD Spectrum of triphenylene 7b in CHCl3 (c ˆ 10À3 mol lÀ1) (left) and in hexane (c ˆ 10À3 mol lÀ1) (right).
The grey area indicates the range of wavelength where no significant measurement is possible due to the
absorption of the solvent.
small helical twisting of the columnar aggregates resulting from the in part quite remote
chiral centers in the side chain with respect to the central triphenylene chromophore.
Conclusions. We have shown that chiral triphenylenes 7a,b with highly branched
alkanoic acid derived side chains can be used to form mesophases in mixtures with

Helvetica Chimica Acta Vol. 85 (2002)
3915
achiral triphenylenes although compounds 7a,b are nonmesomorphic. In addition,
compounds 7a,b form helical aggregates in solution.
Generous financial support by the Deutsche Forschungsgemeinschaft (LA 907/3-2, LA 907/3-3, and
Graduiertenkolleg −Elektronendichte×) and the Fonds der Chemischen Industrie is gratefully acknowledged. We
would like to thank Ms. Hillmann for technical assistance with DSC measurements.
Experimental Part
General. FC ˆ flash chromatography. NMR Spectra: Bruker AM-400 and Bruker AC-200-P; d in ppm and J
in Hz. Differential-scanning calorimetry: Rheometric Scientific DSC-SP and Perkin-Elmer DSC-7; heating and
cooling rate, 10 K minÀ1. Polarizing microscopy: Olympus-BX50 polarizing microscope combined with a
Linkam LTS350 hot stage and Linkam TP-93 central processor. Circular dichroism spectra: Jasco J-715; cell
length 0.5 mm, band width 1.0 nm, scanning speed 200 nm minÀ1, response time 0.25 s. EI-MS: in m/z (rel. %).
Triphenylene-2,3,6,7,10,11-hexol (6) was prepared according to [12], 2,3,6,7,10,11-hexakis(octyloxy)triphe-
nylene (HAT8) and 2,3,6,7,10,11-hexakis(decyloxy)triphenylene (HAT10) were prepared according to [13].
(2R,4R,6R)-2,4,6-Trimethyloctan-1-ol (2a). Methyl (2R,4R,6R)-2,4,6-trimethyloctanoate (1a; 12.0 g,
0.06 mol) was added dropwise to a suspension of LiAlH4 (7.30 g, 0.19 mol) in Et2O (70 ml) while maintaining
gentle refluxing. Then the mixture was refluxed for 5 h. After cooling to r.t., the mixture was carefully
hydrolyzed under ice-cooling by subsequent dropwise addition of H2O (7 ml), 10% NaOH soln. (7 ml), and
H2O (21 ml), and the resulting suspension was stirred for 1 h. The precipitate was removed by filtration and
washed with Et2O, and the combined org. layer was dried (MgSO4) and evaporated: 9.94 g (96%) of 2a.
Colorless liquid. [a]2D0 ˆ ‡6.1 (c ˆ 1.00, CHCl3). 1H-NMR (400 MHz, CDCl3): 3.53 (dd, J ˆ 5.0, 10.4, HaÀC(1));
3.36 (dd, J ˆ 6.8, 10.4, HbÀC(1)); 1.76 1.68 (m, HÀC(2)); 1.61 1.51 (m, HÀC(4)); 1.54 1.18 (m, HÀC(6),
HaÀC(7), HaÀC(5), HaÀC(3)); 1.08 0.99 (m, HbÀC(7)); 0.92 (d, J ˆ 6.6, MeÀC(2)); 0.86 (d, J ˆ 6.3,
MeÀC(4)); 0.83( d, J ˆ 6.6, MeÀC(6)); 0.93 0.82 ( m, HbÀC(5), HbÀC(3), Me(8)). 13C-NMR (100 MHz,
CDCl3): 68.3 (C(1)); 44.7 (C(5)); 41.3 (C(3)); 33.1 (C(2)); 31.5 (C(6)); 28.8 (C(7)); 27.5 (C(4)); 20.9
(MeÀC(4)); 19.9 (MeÀC(6)); 17.5 (MeÀC(2)), 11.1 (C(8)).
(2R,4R,6R,8R)-2,4,6,8-Tetramethyldecan-1-ol (2b). As described for 2a, with 1b: 11.5 g (quant.) of 2b.
Colorless liquid. [a]2D0 ˆ ‡2.95 (c ˆ 1.08, CHCl3). 1H-NMR (400 MHz, CDCl3): 3.54 (dd, J ˆ 5.0, 10.4,
HaÀC(1)); 3.36 (dd, J ˆ 6.8, 10.4, HbÀC(1)); 1.76 1.68 (m, HÀC(2)); 1.62 1.52 (m, HÀC(4), HÀC(6));
1.46 1.15 (m, HÀC(8), HaÀC(9), HaÀC(3), HaÀC(7), HaÀC(5)); 1.09 0.99 (m, HbÀC(9)); 0.93( d, J ˆ 6.8,
MeÀC(2)); 0.86 (d, J ˆ 6.3, MeÀC(4)); 0.84 (d, J ˆ 6.6, MeÀC(8)); 0.83( d, J ˆ 6.6, MeÀC(6)); 0.92 0.80
(m, HbÀC(3), HbÀC(5), Me(10), HbÀC(7)). 13C-NMR (100 MHz, CDCl3): 68.2 (C(1)); 45.5 (C(5)); 44.6
(C(7)); 41.1 (C(3)); 33.1 (C(2)); 31.5 (C(8)); 28.7 (C(9)); 27.5 (C(4), C(6)); 21.0 (MeÀC(4), MeÀC(6)); 20.0
(MeÀC(8)); 17.6 (MeÀC(2)); 11.1 (C(10)).
Bromides 3a,b: General Procedure. A soln. of Br2 (5.1 ml, 0.10 mol) in CH2Cl2 (15 ml) was added dropwise
at 08 to a soln. of PPh3 (26.2 g, 0.10 mol) in CH2Cl2 (300 ml), and the resulting suspension was stirred for 30 min
at 08. Then 2a,b (0.10 mol) was added at 08, and the mixture was stirred for 18 h at r.t. The org. layer was washed
with sat. Na2SO3 soln. (200 ml) and H2O (200 ml) and dried (MgSO4). Upon evaporation of the solvent, Ph3PO
precipitated from the soln., which was removed by filtration. The precipitate was washed with pentane, the
combined filtrate evaporated, and the residue purified by FC (SiO2 ; pentane): 3a,b as colorless liquids.
1
(2R,4R,6R)-1-Bromo-2,4,6-trimethyloctane (3a): 10.8 g (92%). [a]2D0 ˆ À15.0 (c ˆ 2.00, CHCl3). H-NMR
(400 MHz, CDCl3): 3.42 (dd, J ˆ 4.0, 9.8, HaÀC(1)); 3.32 (dd, J ˆ 6.0, 9.8, HbÀC(1)); 1.93 1.86 ( m, HÀC(2));
1.59 1.52 (m, HÀC(4)); 1.47 1.30 (m, HÀC(6), HaÀC(3), HaÀC(7)); 1.24 1.17 (m, HaÀC(5)); 1.11 1.02
(m, HbÀC(7)); 1.01 (d, J ˆ 6.6, MeÀC(2)); 0.86 (d, J ˆ 6.0, MeÀC(4)); 0.85 (d, J ˆ 6.6, MeÀC(6)); 0.99 0.84
(m, HbÀC(3), HbÀC(5), Me(8)). 13C-NMR (100 MHz, CDCl3): 44.8 (C(5)); 42.6 (C(3)); 41.6 (C(1)); 32.3
(C(2)); 31.5 (C(6)); 29.0 (C(7)); 27.4 (C(4)); 20.6 (MeÀC(4)); 19.8 (MeÀC(6)); 19.7 (MeÀC(2)); 11.1 (Me(8)).
(2R,4R,6R,8R)-1-Bromo-2,4,6,8-tetramethyldecane (3b): 13.2 g (95%). [a]2D0 ˆ À13.6 (c ˆ 2.00, CHCl3).
1H-NMR (400 MHz, CDCl3): 3.43 (dd, J ˆ 4.0, 9.8, HaÀC(1)); 3.32 (dd, J ˆ 6.0, 9.8, HbÀC(1)); 1.93 1.85
(m, HÀC(2)); 1.63 1.52 ( m, HÀC(6), HÀC(4)); 1.47 1.32 (m, HÀC(8), HaÀC(3), HaÀC(9)); 1.24 1.15
(m, HaÀC(7), HaÀC(5)); 1.01 (d, J ˆ 6.6, MeÀC(2)); 1.09 0.84 (m, HbÀC(9), HbÀC(3), HbÀC(5), Me(10),
HbÀC(7), MeÀC(4), MeÀC(6), MeÀC(8)). 13C-NMR (100 MHz, CDCl3): 45.6 (C(5)); 44.7 (C(7)); 42.3
(C(3)); 41.5 (C(1)); 32.3 (C(2)); 31.5 (C(8)); 28.9 (C(9)); 27.4 (C(4), C(6)); 20.9 (MeÀC(8)); 20.7 (MeÀC(4));
‡
20.0 (MeÀC(6)); 19.8 (MeÀC(2)); 11.2 (Me(10)). EI-MS: 278 (2), 276 (2, M ), 249 (2), 247 (2), 207 (4), 205

3916
Helvetica Chimica Acta Vol. 85 (2002)
(4), 179 (6), 177 (6), 165 (36), 163 (37), 151 (1), 149 (1), 141 (8), 125 (11), 111 (7), 99 (18), 85 (21), 83 (43), 71
(42), 57 (100), 55 (39).
1,2-Bis(alkyloxy)benzenes 5a,b: General Procedure. Compound 3a,b (27.0 mmol) was added dropwise to a
suspension of K2CO3 (5.60 g, 40.5 mmol) and catechol (ˆ benzene-1,2-diol; 4; 1.49 g, 13.5 mmol) in DMF
(40 ml), and the resulting mixture was stirred at 808 for 2 d. After cooling to r.t., H2O (100 ml) was added, the
aq. layer extracted with Et2O (2 Â 100 ml) and the combined org. layer washed with H2O (4 Â 100 ml), dried
(MgSO4), and evaporated. Purification by FC (SiO2, hexanes/ethyl AcOEt 40 :1) yielded 5a,b as colorless
liquids.
1,2-Bis{[(2R,4R,6R)-2,4,6-trimethyloctyl]oxy}benzene (5a): 3.48 g (62%). [a]2D0 ˆ À14.4 (c ˆ 1.00, CHCl3).
1H-NMR (400 MHz, CDCl3): 6.89 (m, 4 arom. H); 3.88 (dd, J ˆ 5.0, 8.8, 2 H, HaÀC(1')); 3.71 (dd, J ˆ 7.0, 8.8,
2 H, HbÀC(1')); 2.14 2.06 (m, 2 H, HÀC(2')); 1.70 1.61 (m, 2 H, HÀC(4')); 1.53 1.34 ( m, 6 H, HaÀC(3'),
HÀC(6'), HaÀC(7')); 1.31 1.24 (m, 2 H, HaÀC(5')); 1.12 1.01 (m, 4 H, HbÀC(7'), HbÀC(3')); 1.08 (d, J ˆ 6.6,
6 H, MeÀC(2')); 0.96 0.88 (m, 2 H, HbÀC(5')); 0.91 (d, J ˆ 6.6, 6 H, MeÀC(4')); 0.87 (t, J ˆ 7.3, 6 H,
MeÀC(8')); 0.85 (d, J ˆ 6.6, 6 H, MeÀC(6')). 13C-NMR (100 MHz, CDCl3): 149.5 (C(1), C(2)); 120.9 (C(4),
C(5)); 113.9 (C(3), C(6)); 74.2 (C(1')); 44.7 (C(5')); 41.7 (C(3')); 31.5 (C(6')); 30.8 (C(2')); 28.9 (C(7')); 27.5
‡
(C(4')); 21.0 (MeÀC(4')); 19.9 (MeÀC(6')); 18.1 (MeÀC(2')); 11.1 (Me(8')). EI-MS: 418 (10, M ), 264 (11),
125 (2), 121 (3), 110 (100), 97 (6), 85 (14), 71 (15), 57 (38). Anal. calc. for C28H50O2: C 80.31, H 12.04; found:
C 79.93, H 12.10.
1,2-Bis{[(2R,4R,6R,8R)-2,4,6,8-tetramethyldecyl]oxy}benzene (5b): 3.39 g (67%). [a]2D0 ˆ À7.90 (c ˆ 1.01,
CHCl3). 1H-NMR (400 MHz, CDCl3): 6.88 (m, 4 arom. H); 3.88 (dd, J ˆ 5.0, 8.8, 2 H, HaÀC(1')); 3.70 (dd, J ˆ
7.1, 8.8, 2 H, HbÀC(1')); 2.12 2.04 (m, 2 H, HÀC(2')); 1.69 1.55 (m, 4 H, HÀC(4'), HÀC(6')); 1.52 1.33
(m, 6 H, HaÀC(3'), HÀC(8'), HaÀC(9')); 1.27 1.19 (m, 4 H, HaÀC(5'), HaÀC(7')); 1.07 (d, J ˆ 6.6, 6 H,
MeÀC(2')); 1.10 0.97 (m, 4 H, HbÀC(9'), HbÀC(3')); 0.90 (d, J ˆ 6.6, 6 H, MeÀC(4')); 0.85 (d, J ˆ 6.6, 6 H,
MeÀC(8')); 0.83( d, J ˆ 6.6, 6 H, MeÀC(6')); 0.93 0.82 ( m, 10 H, HbÀC(5'), HbÀC(7'), Me(10')). 13C-NMR
(100 MHz, CDCl3): 149.5 (C(1), C(2)); 120.9 (C(4), C(5)); 114.0 (C(3), C(6)); 74.2 (C(1')); 45.5 (C(5')); 44.6
(C(7')); 41.5 (C(3')); 31.5 (C(8')); 30.8 (C(2')); 28.8 (C(9')); 27.5 (C(4'), C(6')); 21.1, 21.0 (MeÀC(4'),
‡
MeÀC(6')); 20.0 (MeÀC(8')); 18.2 (MeÀC(2')); 11.1 (Me(10')). EI-MS: 502 (44, M ), 306 (18), 196 (2), 149
(1), 139 (5), 125 (11), 110 (100), 71 (54), 69 (76), 57 (96). Anal. calc. for C34H62O2: C 81.20, H 12.44; found:
C 80.99, H 12.60.
Hexakis(alkyloxy)triphenylenes 7a,b: General Procedures. Method A. MoCl5 (410 mg, 1.50 mmol) was
added to a soln. of 5a,b (1.50 mmol) in CH2Cl2 (3ml), and the mixture was stirred for 20 min at r.t. Then the
mixture was treated subsequently with MeOH (5 ml) and H2O (6 ml), and the aq. layer was extracted with
hexanes (4 Â 50 ml). The combined org. layer was washed with brine (2 Â 75 ml), dried (MgSO4), and
evaporated. Purification by FC (2 Â ; SiO2 ; hexanes/CH2Cl2 3:1) yielded 7a,b as colorless oils.
Method B. Compound 6 (1.54 mmol) and 3a,b (0.01 mol) were added to a suspension of K2CO3 (2.76 g,
0.02 mol) in DMF (25 ml), and the resulting mixture was stirred at 1008 for 20 h. After cooling to r.t., the
mixture was diluted with H2O (60 ml) and extracted with pentane (3 Â 60 ml). The combined org. layer was
washed with H2O (4 Â 60 ml), dried (MgSO4), and evaporated, and the crude 7a,b purified as described in
Method A.
2,3,6,7,10,11-Hexakis{[(2R,4R,6R)-2,4,6-trimethyloctyl]oxy}triphenylene (7a): 120 mg (19%) by Meth-
od A; 910 mg (47%) by Method B. [a]2D0 ˆ À29.1 (c ˆ 1.00, CHCl3). 1H-NMR (400 MHz, CDCl3): 7.82
(s, 6 arom. H); 4.14 (dd, J ˆ 5.0, 8.8, 6 H, HaÀC(1')); 3.96 (dd, J ˆ 6.8, 8.8, 6 H, HbÀC(1')); 2.27 2.19
(m, 6 H, HÀC(2')); 1.75 1.69 (m, 6 H, HÀC(4')); 1.65 1.58 (m, 6 H, HaÀC(3')); 1.55 1.27 (m, 18 H,
HÀC(6'), HaÀC(7'), HaÀC(5')); 1.17 (d, J ˆ 6.8, 18 H, MeÀC(2')); 1.18 1.04 (m, 12 H, HbÀC(3'), HbÀC(7'));
1.00 0.93( m, 6 H, HbÀC(5')); 0.97 (d, J ˆ 6.6, 18 H, MeÀC(4')); 0.89 0.86 (m, 36 H, Me(8'), MeÀC(6')).
13C-NMR (100 MHz, CDCl3): 149.2 (C(2), C(3), C(6), C(7), C(10), C(11)); 123.5 (C(1a), C(4a), C(5a), C(8a),
C(9a), C(12a)); 106.9 (C(1), C(4), C(5), C(8), C(9), C(12)); 74.4 (C(1')); 44.7 (C(5')); 41.7 (C(3')); 31.5
(C(6')); 30.9 (C(2')); 29.0 (C(7')); 27.5 (C(4')); 21.1 (MeÀC(4')); 19.9 (MeÀC(6')); 18.2 (MeÀC(2')); 11.2
‡
(Me(8')). EI-MS: 1249 (43, M ), 1094 (4), 939 (5), 785 (3), 631 (14), 477 (7), 324 (30), 295 (10), 218 (16), 125
(3), 83 (24), 69 (33), 57 (100). Anal. calc. for C 84H144O6: C 80.70, H 11.62; found: C 80.71, H 11.91.
2,3,6,7,10,11-Hexakis{[(2R,4R,6R,8R)-2',4',6',8'-tetramethyldecyl]oxy}triphenylene (7b): 1.10 g (44%) by
Method A; 1.03g (45%) by Method B. [a]D20 ˆ À16.8 (c ˆ 1.00, CHCl3). 1H-NMR (400 MHz, CDCl3): 7.82
(s, 6 arom. H); 4.14 (dd, J ˆ 5.0, 8.8, 6 H, HaÀC(1')); 3.96 (dd, J ˆ 6.8, 8.8, 6 H, HbÀC(1')); 2.26 2.18 (m, 6 H,
HÀC(2')); 1.78 1.57 (m, 18 H, HÀC(4'), HÀC(6'), HaÀC(3')); 1.49 1.22 (m, 24 H, HÀC(8'), HaÀC(9'),
HaÀC(5'), HaÀC(7')); 1.18 (d, J ˆ 6.6, 18 H, MeÀC(2')); 1.14 1.00 (m, 12 H, HbÀC(3'), HbÀC(9')); 0.97
(d, J ˆ 6.6, 18 H, MeÀC(4')); 0.98 0.84 (m, 66 H, HbÀC(5'), HbÀC(7'), MeÀC(6'), MeÀC(8'), Me(10')).

Helvetica Chimica Acta Vol. 85 (2002)
3917
13C-NMR (100 MHz, CDCl3): 149.2 (C(2), C(3), C(6), C(7), C(10), C(11)); 123.5 (C(1a), C(4a), C(5a), C(8a),
C(9a), C(12a)); 106.9 (C(1), C(4), C(5), C(8), C(9), C(12)); 74.3(C(1 ')); 45.4 (C(5')); 44.7 (C(7')); 41.4
(C(3')); 31.6 (C(8')); 30.9 (C(2')); 28.8 (C(9')); 27.5 (C(4'), C(6')); 21.3, 21.0 (MeÀC(4'), MeÀC(6')); 20.0
‡
(MeÀC(8')); 18.3( MeÀC(2')); 11.2 (Me(10')). EI-MS: 1501 (56, M ), 1304 (10), 1108 (4), 913 (2), 715 (18),
519 (10), 323 (42), 295 (17), 149 (21), 97 (36), 85 (60), 71 (81), 57 (100). Anal. calc. for C102H180O6: C 81.53,
H 12.08; found: C 81.35, H 12.28.
REFERENCES
[1] S. Chandrasekhar, Liq. Cryst. 1993, 14. 3 .
[2] A. N. Cammidge, R. J. Bushby, in − Handbook of Liquid Crystals×, Eds. D. Demus, J. Goodby, G. W. Gray,
H.-W. Spiess, and V. Vill, Wiley-VCH, Weinheim, 1998, Vol. 2 B, p. 693; S. Chandrasekhar, in − Handbook
of Liquid Crystals×, Vol. 2 B, p. 749.
[3] S. Kumar, S. K. Varshney, Org. Lett. 2002, 4, 157; J. Barbera, A. C. Garces, N. Jayaraman. A. Omenat, J. L.
Serrano, J. F. Stoddart, Adv. Mater. 2001, 13, 175; S. Kumar, S. K. Varshney, Synthesis 2001, 305; R. J.
Bushby, Z. Lu, Synthesis 2001, 763; D. Hirst, S. Diele, S. Laschat, M. Nimtz, Helv. Chim. Acta 2001, 84, 1190;
A. Rose, C. G. Lugmair, T. M. Swager, J. Am. Chem. Soc. 2001, 123, 11298; J. Kim, D. T. Mc Quade, A.
Rose, Z. Zhu, T. M. Swager, J. Am. Chem. Soc. 2001, 123, 11488; A. Schultz, S. Laschat, A. P. Abbott, M.
Langner, T. B. Reeve, J. Chem. Soc., Perkin Trans. 1 2000, 3356; E. O. Arikainen, N. Boden, R. J. Bushby,
O. R. Lozman, J. G. Vinter, A. Wood, Angew. Chem. 2000, 112, 2423; Angew. Chem., Int. Ed. 2000, 39, 23 3 ;
G. Cooke, A. Radhi, N. Boden, R. J. Bushby, Z. Lu, S. Brown, S. L. Heath, Tetrahedron 2000, 56, 3 3 85; G.
Cooke, N. Kaushal, N. Boden, R. J. Bushby, Z. Lu, O. Lozman, Tetrahedron Lett. 2000, 41, 7955; N. Boden,
R. J. Bushby, Z. Lu, G. Headdock, Tetrahedron Lett. 2000, 41, 10117; S. Mahlstedt, D. Janietz, A. Stracke,
J. H. Wendorff, Chem. Commun. 2000, 15; J. L. Schulte, S. Laschat, V. Vill, E. Nishikawa, H. Finkelmann,
M. Nimtz, Eur. J. Org. Chem. 1998, 2499; S. Kumar, P. Schuhmacher, P. Henderson, J. Rego, H. Ringsdorf,
Mol. Cryst. Liq. Cryst. 1996, 288, 211; D. Adam, P. Schuhmacher, J. Simmerer, L. H‰ussling, W. Paulus, K.
Siemensmeyer, K. H. Etzbach, H. Ringsdorf, D. Haarer, Adv. Mater. 1995, 7, 276; N. Boden, R. J. Bushby,
A. N. Cammidge, J. Am. Chem. Soc. 1995, 117, 924; S. Disch, H. Finkelmann, H. Ringsdorf, P. Schuhmacher,
Macromolecules 1995, 28, 2424; I. Voigt-Martin, M. Schuhmacher, M. Honig, P. Simon, R. Garbella, Mol.
Cryst. Liq. Cryst. Sci. Technol., Sect. A 1994, 254, 299; S. Zamir, R. Poupko, Z. Luz, B. Huser, C. Boeffel, H.
Zimmermann, J. Am. Chem. Soc. 1994, 116, 1973; M. Mˆller, V. Tsukruk, J. H. Wendorff, H. Bengs, H.
Ringsdorf, Liq. Cryst. 1992, 12, 17; W. Kranig, B. H¸ser, H.-W. Spiess, W. Kreuder, H. Ringsdorf, H.
Zimmermann, Adv. Mater. 1990, 2, 36; W. Kranig, C. Boeffel, H.-W. Spiess, O. Karthaus, H. Ringsdorf, R.
W¸stefeld, Liq. Cryst. 1990, 8, 375.
[4] N. Boden, B. Movaghar, in − Handbook of Liquid Crystals×, Vol. 2 B, p. 781; J. Kopitzke, J. H. Wendorff,
Chem. unserer Zeit 2000, 34, 4; C. F. van Nostrum, Adv. Mater. 1996, 8, 1027.
[5] K. Ishimura, S. Furumi, S. Morino, M. Kidowaki, M. Nakagawa, M. Ogawa, Y. Nishiura, Adv. Mater. 2000,
12, 950; H. Monobe, K. Awazu, Y. Shimizu, Adv. Mater. 2000, 12, 1495; B. A. Gregg, M. A. Fox, A. J. Bard,
J. Phys. Chem. 1989, 93, 4227.
[6] D. Markovitsi, N. Pfeffer, F. Charra, J.-M. Nunzi, H. Bengs, H. Ringsdorf, J. Chem. Soc., Faraday Trans.
1993, 89, 37; D. Markovitsi, H. Bengs, H. Ringsdorff, J. Chem. Soc., Faraday Trans. 1992, 88, 1275; M. M.
Green, H. Ringsdorff, J. Wagner, R. W¸stefeld, Angew. Chem. 1990, 102, 1525; Angew. Chem., Int. Ed.
1990, 29, 1478.
[7] J. P. Gallivan, G. B. Schuster, J. Org. Chem. 1995, 60, 2423.
[8] M. Weck, A. R. Dunn, K. Matsumoto, G. W. Coates, E. B. Lobkovsky, R. H. Grubbs, Angew. Chem. 1999,
111, 2909; Angew. Chem., Int. Ed. 1999, 38, 2741; C. V. Yelamaggad, V. Prasad, M. Manickam, S. Kumar,
Mol. Cryst. Liq. Cryst. 1998, 325, 33; K. Praefcke, A. Eckert, D. Blunck, Liq. Cryst. 1997, 22, 113; N. Boden,
R. G. Bushby, A. N. Cammidge, S. Duckworth, G. Headdock, J. Mater. Chem. 1997, 7, 604; G. Heppke, D.
Kr¸erke, M. M¸ller, H. Bock, Ferroelectrics 1996, 179, 203; J. P. Gallivan, G. B. Schuster, J. Org. Chem.
1995, 60, 2423; H. Bock, W. Helfrich, G. Heppke, EP 529439, 1992; Chem. Abstr. 1992, 119, 170902; M.
Werth, S. U. Vallerien, H.-W. Spiess, Liq. Cryst. 1991, 10, 759; J. Malthete, J. Jacques, N. H. Tinh, C.
Destrade, Nature (London) 1982, 298, 46; J. Malthete, C. Destrade, N. H. Tinh, Mol. Cryst. Liq. Cryst. 1981,
64, 233; C. Destrade, T. H. Nguyen, J. Malthete, J. Jacques, Phys. Lett. A 1980, 79, 189.

3918
Helvetica Chimica Acta Vol. 85 (2002)
[9] M. Morr, C. Proppe, V. Wray, Liebigs Ann. Chem. 1995, 2001; M. Morr, V. Wray, J. Fortkamp, R. D.
Schmid, Liebigs Ann. Chem. 1992, 433; J. Fortkamp, Dissertation, Technische Universit‰t Braunschweig,
1994.
[10] G. Heppke, D. Lˆtzsch, M. Morr, L. Ernst, J. Mater. Chem. 1997, 7, 1993.
[11] S. Kumar, M. Manickam, Chem. Commun. 1997, 1615.
[12] M. Rey-Ifon, C. Destrade, A. T. Hemida, Mol. Cryst. Liq. Cryst. 1986, 137, 381; N. H. Tinh, H. Gasparoux,
C. Destrade, Mol. Cryst. Liq. Cryst. 1981, 68, 101.
[13] N. H. Tinh, M. C. Bernhard, G. Sigaud, C. Destrade, Mol. Cryst. Liq. Cryst. 1981, 65, 307.
[14] J. W. Goodby, G. W. Gray, in − Handbook of Liquid Crystals×, Eds. D. Demus, J. Goodby, G. W. Gray, H.-W.
Spiess, and V. Vill, Wiley-VCH, Weinheim, 1998, Vol. 1, p. 17.
[15] D. Demus, L. Richter, −Textures of Liquid Crystals×, 2nd edn., VEB Deutscher Verlag f¸r Grundstoffin-
dustrie, Leipzig, 1980, p. 174.
Received August 14, 2002