Enantiopure Trioxadecalin Derived Liquid Crystals: Influence of the Nature of the Phenyl Substituent on the Mesogenic Properties

Article abstract of DOI:10.1081/CAR-120026468

Reaction of pseudo-glucal 1 with Grignard reagents derived from 1-bromo-4-(trimethylsilyloxy)benzene, 1-bromo-4-methoxybenzene, 1-bromo-4-methoxymethoxybenzene, 1-bromo-4-dimethylaminobenzene, in the presence of a catalytic amount of NiCl₂(dppe

Full text of DOI:10.1081/CAR-120026468

Journal of Carbohydrate Chemistry
ISSN: 0732-8303 (Print) 1532-2327 (Online) Journal homepage: http://www.tandfonline.com/loi/lcar20
Enantiopure Trioxadecalin Derived Liquid Crystals:
Influence of the Nature of the Phenyl Substituent
on the Mesogenic Properties
Bruno Bertini , Monique Perrin , Denis Sinou , Alain Thozet & Volkmar Vill
To cite this article: Bruno Bertini , Monique Perrin , Denis Sinou , Alain Thozet & Volkmar Vill
(2003) Enantiopure Trioxadecalin Derived Liquid Crystals: Influence of the Nature of the Phenyl
Substituent on the Mesogenic Properties , Journal of Carbohydrate Chemistry, 22:7-8, 685-703,
DOI: 10.1081/CAR-120026468
To link to this article: http://dx.doi.org/10.1081/CAR-120026468
Published online: 23 Feb 2007.
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Date: 18 January 2016, At: 05:47

JOURNAL OF CARBOHYDRATE CHEMISTRY
Vol. 22, Nos. 7 & 8, pp. 685–703, 2003
Enantiopure Trioxadecalin Derived Liquid
Crystals: Influence of the Nature of the
Phenyl Substituent on the
Mesogenic Propertiesy
Bruno Bertini,1 Monique Perrin,2 Denis Sinou,1,
*
Alain Thozet,2 and Volkmar Vill3
2
1Laboratoire de Synthe`se Asyme´trique and Laboratoire de Cristallographie,
associe´ au CNRS, Universite´ Claude Bernard Lyon 1,
Villeurbanne ce´dex, France
3Institute of Organic Chemistry, University of Hamburg, Hamburg, Germany
ABSTRACT
Reaction of pseudo-glucal 1 with Grignard reagents derived from 1-bromo-4-
(trimethylsilyloxy)benzene, 1-bromo-4-methoxybenzene, 1-bromo-4-methoxyme-
thoxybenzene, 1-bromo-4-dimethylaminobenzene, in the presence of a catalytic
amount of NiCl2(dppe), gives the corresponding unsaturated b-C-aryl glycosides 2.
Desilylation and hydrogenation of 2 leads to b-C-aryl glycosides 4, which can be
used as chiral precursor compounds in the synthesis of chiral liquid crystals.
Combination of 4 with arylaldehydes leads to compounds 5–7, whereas reaction with
p-alkoxysubstituted phenylboronic acids gives the trioxaboradecalins 8–11. The
yThis paper is dedicated to Professor Ge´rard Descotes on the occasion of his 70th birthday.
*
Correspondence: Denis Sinou, Laboratoire de Synthe`se Asyme´trique, associe´ au CNRS, CPE
Lyon, Universite´ Claude Bernard Lyon 1, 43, boulevard du 11 novembre 1918, 69622 Villeurbanne
ce´dex, France; Fax: 33 4 78 89 89 14; E-mail: sinou@univ-lyon1.fr.
685
DOI: 10.1081/CAR-120026468
0732-8303 (Print); 1532-2327 (Online)
www.dekker.com
Copyright D 2003 by Marcel Dekker, Inc.

686
Bertini et al.
mesogenic properties of these compounds are strongly influenced by the nature of the
substituent on the phenyl ring in the molecule.
Key Words: C-Glycosides; Trioxadecalins; Trioxaboradecalins; Liquid crystals;
Chirality.
INTRODUCTION
Chirality has become one of the most important and complex topics in liquid crystal
research during the last decade.[1] Effectively, molecular asymmetry imparts form
chirality to the liquid crystalline phases; in addition possible new technical applications
for chiral liquid crystals can be found. Today, 16,000 of the 80,000 mesogenic known
compounds are chiral,[2] most of them having a stereogenic center in the flexible wing,
which induces chirality by steric hindrance and disturbs the mesogenic order.
Previously, V. Vill and coworkers prepared new liquid crystals bearing a chiral
trioxadecalin core.[3–9] These compounds exhibited interesting chiral effects such as
cholesteric helix inversion, double inversion of the helical twist sense, and re-entrant
TGBA phases. All the studied substrates had the alkoxy chain directly bound to the
para position of the phenyl ring linked to the pyranosyl moiety. We recently published
the synthesis of a homologous series of trioxadecalin derivatives bearing a terminal
halogen or trifluoromethyl group on the para position on this aromatic ring, and alkoxy
substituents on the para position of the phenyl ring directly linked to the dioxolane
moiety, and examined the influence of these substituents on the mesogenic properties
of these compounds.[10] In the continuation of this work, we present in this paper the
synthesis and the mesogenic properties of analogs bearing a hydroxy, a methoxy, a
methoxymethoxy, or a dimethylamino group on the para position of the phenyl ring.
RESULTS AND DISCUSSION
The preparation of the building blocks 4, used as starting materials in the syn-
thesis of the new liquid crystals bearing a chiral trioxadecalin system, is described in
Scheme 1.
The reaction of the Grignard reagents prepared from 1-bromo-4-(trimethylsily-
loxy)benzene, 1-bromo-4-methoxybenzene, 1-bromo-4-methoxymethoxybenzene, or 1-
bromo-4-dimethylaminobenzene, with p-tert-butylphenyl 4,6-di-O-(tert-butyldimethyl-
silyl)-2,3-dideoxy-a-D-erythro-hex-2-enopyranoside (1)[11] in the presence of a catalytic
amount of NiCl2(dppe) [dppe = 1,2-bis(diphenylphosphino)ethane] in tetrahydrofuran at
ꢀ40°C gave regio- and stereospecifically the corresponding b-C-arylglycosides 2a, 2b,
2c, and 2d, in 48%, 51%, 80%, and 80% yield, respectively. It is to be noted that
cleavage of the trimethysilyl group observed in the preparation of 2a occurred readily
during the aqueous treatment as well as upon purification by column chromatography.
Desilylation of compounds 2a–d was mediated by hydrated tetrabutylammonium
fluoride in tetrahydrofuran to give the unsaturated diols 3a, 3b, 3c, and 3d, in 80%,
80%, 90%, and 80% yield, respectively. Hydrogenation of diols 3a–d at atmospheric
pressure in ethanol in the presence of the catalyst [Rh(COD)(dppb)]ClO4 [COD:
1,5-cyclooctadiene; dppb:1,4-bis(diphenylphosphino)butane] gave the corresponding

Enantiopure Trioxadecalin Derived Liquid Crystals
687
Scheme 1. Synthesis of building blocks 4. Reagents and conditions: i: BrMgC6H4-p-R,
NiCl2(dppe), THF; ii: Bu4NF, THF, 25°C; iii: H2, [Rh(COD)(dppb)]ClO4, EtOH.
saturated diols 4a, 4b, 4c, and 4d, in 65%, 60%, 60%, and 83% yield after column
chromatography, respectively. 1H NMR data confirmed the b configuration of
compounds 4a–d as expected from previous work in this field.[11] Indeed for these
compounds, a large diaxial coupling constant was observed between H-1 and H-2ax
(3J1,2ax = 10.2, 8.2, 10.4, and 11.0 Hz for 4a, 4b, 4c, and 4d, respectively), together
3
with a small coupling constant J1,2eq between H-1 and H-2eq (3J1,2eq = 2.1, 2.3, 2.2,
and 2.2 Hz for 4a, 4b, 4c, and 4d, respectively). The conversion of diols 4a–d to
trioxadecalins 5–7 was carried out with the corresponding dimethyl acetals of 4-alko-
xybenzaldehyde based on an acid-catalyzed transacetalization reaction, the methanol
formed being distilled off to shift the equilibrium of the reaction (Scheme 2). On the
other hand, the boronic acid derivatives 8–11 were easily obtained from diols 4a–d and
the appropriate arylboronic acid, the water formed being removed by azeotropic co-
evaporation with toluene (Scheme 2). All the products were recrystallized from ethanol.
The mesomorphic properties of compounds 5–7 are summarized in Table 1. For
trioxadecalins 5a and 5d, we observed only an enantiotropic cholesteric phase, in
agreement with Vill and coworker’s previous results on similar compounds.[7] The
trioxadecalins 6a–d, containing a methoxymethoxy substituent, had a similar
behaviour, although it was not possible to determine the exact transition temperature
for compounds 6b–d. However, there is little influence of the chain length of the
alkoxy substituent on the transition temperature of the crystalline phase. It is to be
noticed that the analogous compound having a trifluoromethoxy group in the para
position and previously described exhibited a quite different behaviour;[10]
a
monotropic cholesteric mesophase and an enantiotropic SA mesophase were observed
for n = 1 and 4, but no mesogenic property when n = 8.
For trioxadecalins 7a–d, having a dimethylamino substituent, the melting point
decreased with increasing chain length. We observed a cholesteric phase, that is
monotropic for 7b and enantiotropic for all other compounds in the series. By

688
Bertini et al.
Scheme 2. Synthesis of compounds 5–11. Reagents and conditions: i: p-CnH2n+1O-C6H4-
CH(OMe)2, DMF, p-TsOH; ii: p-CnH2n+1O-C6H4-B(OH)2, toluene, 45°C.
comparison of these compounds 7a–d with the analogous chloro derivatives,[10] we
observed that the cholesteric phase appeared at a lower temperature when the para
substituent was a dimethylamino group.
The mesomorphic properties of the boratrioxadecalin compounds 8–11 are also
compiled in Table 1. As previously noted in similar structures, the replacement of the
carbon atom in the trioxadecalin system by a boron atom was expected to result in a
change of the mesogenic properties of the target compounds.
Indeed, compound 8a showed no mesogenic property. However, compound 8c
showed an SA phase, a TGBA phase, and a cholesteric phase, whereas compound 8d
exhibited only a smectic A phase. In this case, the increasing chain length obviously
stabilized the lamellar SA phase.
For compounds 9a–d bearing a methoxy substituent, the melting point decreased
with increasing chain length. These compounds exhibited a high clearing temperature
and a broad enantiotropic cholesteric phase, ranging from 10°C (for 5) to from 60 to
90°C (for 9). This difference is probably due to the substitution of the tetrahedral
carbon atom by the planar boron atom, leading to a different binding angle of the left
alkoxyphenyl unit in the two compounds. We also observed a blue phase with the pitch
in the UV for compounds 9a–b. This different behaviour between 8a–d and 9a–d
could be due to the formation of an intermolecular hydrogen bond in the case of 8a–d,
due to the presence of the p-hydroxyl function. Compounds 9a–d, as compared with
the analogues bearing a trifluoromethoxy substituent in the para position[10] clearly
show only an enantiotropic cholesteric phase, while the corresponding trifluoromethoxy
analogues display a smectic A phase.

Enantiopure Trioxadecalin Derived Liquid Crystals
689

690
Bertini et al.
Although both series shared the methoxymethoxy substituent, compounds 10a–d
exhibited a behaviour quite different from that of compounds 6a–d. In the latter series,
the melting point decreased with increasing chain length. For compound 10a, we
observed two crystal-crystal transitions, and a unique enantiotropic cholesteric phase.
Conversely, compounds 10b–d showed a SA phase, a TGBA phase and a cholesteric
phase. In addition, all compounds exhibited a blue phase with the pitch in the UV.
Compounds 11 have very high clearing temperatures, which resemble those of
compounds 7, and exhibited a cholesteric phase that is monotropic for 11a and
enantiotropic for 11b–d. All compounds showed also a blue phase. We noticed that the
substitution of a methoxy group (compounds 9a–d) by a dimethylamino group
(compounds 11a–d) gave higher transition temperatures for the crystalline phase and
the cholesteric phase.
In order to obtain some more information on the quite different behaviour of these
chiral trioxa- and trioxaboradecalins and eventually to have some information on the
influence of a substitution of a carbon by a boron atom, the structures of compounds 6a
and 10 were determined by single-crystal X-ray diffraction analysis (Figure 1).a
However, the structures of these compounds, in the solid state, seemed very similar and
gave no further information concerning the differences of the mesogenic properties of
these componds.
CONCLUSION
Condensation of various aryl Grignard reagents with p-tert-butylphenyl 4,6-di-O-
(tert-butyldimethylsilyl)-2,3-dideoxy-a-D-erythro-hex-2-enopyranoside in the presence
of a nickel catalyst leads to the formation of the corresponding b-C-aryl-D2-
glycopyranosides, which are the key products for the synthesis of chiral trioxa- and
trioxaboradecalins bearing various substituents such as a hydroxy, a methoxy, a
methoxymethoxy, or a dimethylamino group on the para position of the phenyl ring.
These compounds show short pitch cholesterics, blue phases, TGBA phases and sign
inversion of cholesterics depending on the substitution pattern.
aX-ray data for 6a: C22H26O6, M = 386.43, monoclinic, a = 9.592(2), b = 8.611(2), c = 12.537(3)
3
-3
˚
˚
A, b = 108.95(2)°, V = 979.3(3) A , space group P21, Z = 2, Dc = 1.310 Mg m , m (Mo
ka) = 0.095 mm-1, crystal size 0.25 ꢁ 0.20 ꢁ 0.15 mm. Data were measured at 293 K. R = 0.061,
Rw = 0.140 for 2353 independantly observed reflections with [I > 2s(I)]. X-ray data for 10a:
˚
C21H23BO6, M = 382.2, monoclinic, a = 9.595(2), b = 8.555(2),c = 12.509(2) A, b = 108.54(2)°,
3
-3
-1
˚
V = 973.5(3) A , space group P21, Z = 2, Dc = 1.304 Mg m , m (Mo ka) = 0.094 mm , crystal
size 0.35 ꢁ 0.30 ꢁ 0.15 mm. Data were measured at 173 K. R = 0.055, Rw = 0.142 for 2353
independantly observed reflections with [I > 2s(I)]. For all structures, intensities were measured by
a Nonius Kappa CCD diffractometer using Mo ka radiation (l = 0.71073). The structure was solved
by direct methods and refinements with full matrix least-squares were calculated using SHELX97.
Crystallographic data (excluding structure factors) for the structures of compounds 6a and 10a in
this paper have been deposited with the Cambridge Crystallographic Data Centre as supplementary
publication numbers CCDC 187368 and 187367 respectively. Copies of the data can be obtained,
free of charge, on application to CCDC, 12 Union Road, Cambridge CB2 1EZ, UK [fax: +44 (0) -
1223-336033 or e-mail: deposit@ccdc.cam.ac.uk].

Enantiopure Trioxadecalin Derived Liquid Crystals
691
Figure 1. X-ray structures of compound 6a (upper structure) and compound 10a (lower structure).
EXPERIMENTAL
General methods. All reactions were monitored by TLC (TLC plates GF254
Merck); detection was effected by UV absorbance and spraying with a 9:1 solution of
ethanol-sulfuric acid, followed by heating. Reactions involving organometallic catalysis
were carried out in a Schlenk tube under an inert atmosphere. Tetrahydrofuran was
distilled from sodium/benzophenone. Column chromatography was performed on silica
gel 60 (230–240 mesh, Merck). Optical rotations were recorded using a Perkin-Elmer
241 polarimeter. The NMR spectra (1H, 200 or 400 MHz; 13C, 50 or 100 MHz) were
recorded on a Bruker AMX-200 or AMX-400 spectrometer with SiMe4 as internal
standard. An Olympus BH optical polarizing microscope equipped with a Mettler FP 82
hot stage and a Mettler FP 80 central processor was used to identify thermal transitions
and characterize anisotropic textures. For further verification of the textures, a contact
preparation with N4 (4-butyl-4’-methoxyazoxybenzene, K 16 N 76 I) was carried out.
Analysis by DSC was carried out on a Perkin-Elmer DSC7 instrument using heating
and cooling rates of 5 Kminꢀ1. The following compounds were prepared according to
literature procedures: p-tert-butylphenyl 4,6-di-O-(tert-butyldimethylsilyl)-2,3-dideoxy-
a-D-erythro-hex-2-enopyranoside (1),[11]p-alkoxybenzaldehyde dimethyl acetals,[12]
phenylboronic acids,[13,14] NiCl2(dppe),[15](1S,3R,6R,8R)-3,8-bis(4’-methoxyphenyl)-
2,4,7-trioxabicyclo[4.4.0]decane (5a).[7]
Standard procedure for nickel-catalyzed coupling reaction. To a solution of
the unsaturated carbohydrate 1 (223 mg, 0.44 mmol) and NiCl2(dppe) (23 mg, 0.044
mmol) in 2 mL of THF was slowly added at ꢀ40°C a solution of a Grignard reagent
prepared from magnesium (64 mg, 2.6 mmol) and the appropriate aryl bromide (2.18
mmol) in 5 mL of THF. The reaction was followed by TLC. After 24 h, diethyl ether

692
Bertini et al.
(50 mL) was added, and the ether solution was washed with water (2 ꢁ 10 mL), and
dried. After evaporation of the solvent under reduced pressure, the residue was purified
by column chromatography using the indicated solvents as the eluent to give the
corresponding C-glycoside 2.
[4,6-Di-O-(tert-butyldimethylsilyl)-2,3-dideoxy- -D-erythro-hex-2-enopyrano-
syl]-4-hydroxybenzene (2a): yield 48%; oil; Rf 0.36 (petroleum ether/dichloro-
20
1
methane 1/15); [a]D + 233.8 (c 0.6, CH3OH); H NMR (200 MHz, CDCl3) d 0.08 (s,
6H, SiCH3), 0.14 (s, 6H, SiCH3), 0.91 (s, 9H, SiCMe3), 0.93 (s, 9H, SiCMe3), 3.56
(ddd, 1H, J5,4 = 8.4, J5,6a = 5.9, J5,6b = 1.9 Hz, H-5), 3.82 (dd, 1H, J6a,6b = 11.3,
J6a,5 = 5.9 Hz, H-6a), 3.94 (dd, 1H, J6b,6a = 11.3, J6b,5 = 1.9 Hz, H-6b), 4.30 (dd, 1H,
J4,5 = 8.4, J4,1 = 2.8 Hz, H-4), 5.05 (d, 1H, J1,4 = 2.8 Hz, H-1), 5.72 (d, 1H, J2,3 = 10.3
Hz, H-2), 5.78 (d, 1H, J3,2 = 10.3 Hz, H-3), 7.69 (d, 2H, JH,H = 8.6 Hz, Harom), 7.06 (d,
2H, JH,H = 8.6 Hz, Harom); 13C (50 MHz, CDCl3) d ꢀ5.2, ꢀ5.0, ꢀ4.7, ꢀ4.2, 18.1, 18.5,
25.8, 26.0, 63.5, 64.0, 77.0, 80.8, 115.3,128.7, 129.6, 130.9, 132.9, 155.5.
Anal. Calcd for C24H42O4Si2 (450.77): C, 63.95; H, 9.39. Found: C, 63.94; H, 9.39.
[4,6-Di-O-(tert-butyldimethylsilyl)-2,3-dideoxy- -D-erythro-hex-2-enopyrano-
syl]-4-methoxybenzene (2b): yield 51%; oil; [a]D + 136.6 (c 1.1, CH3OH); 1H
20
NMR (200 MHz, CDCl3) d 0.01 (s, 3H, SiCH3), 0.02 (s, 3H, SiCH3), 0.13 (s, 3H,
SiCH3), 0.14 (s, 3H, SiCH3), 0.89 (s, 9H, SiCMe3), 0.93 (s, 9H, SiCMe3), 3.50 (ddd,
1H, J5,4 = 8.4, J5,6a = 6.3, J5,6b = 1.7 Hz, H-5), 3.77–3.92 (m, 5H, H-6a, H-6b, OCH3),
4.36 (dd, 1H, J4,5 = 8.4, J4,1 = 2.6 Hz, H-4), 5.10 (d, 1H, J1,4 = 2.6 Hz, H-1), 5.73 (d,
1H, J2,3 = 11.0 Hz, H-2), 5.78 (d, 1H, J3,2 = 11.0 Hz, H-3), 6.86 (d, 2H, JH,H = 8.6 Hz,
H
arom), 7.26 (d, 2H, JH,H = 8.6 Hz, Harom); 13C (50 MHz, CDCl3) d ꢀ5.1, ꢀ5.0, ꢀ4.7,
ꢀ4.2, 18.9, 18.5, 25.9, 26.0, 55.3, 63.0, 63.6, 76.8, 80.7, 113.7, 128.4, 129.8, 130.8,
133.6, 159.2.
Anal. Calcd for C25H44O4Si2 (464.80): C, 64.60; H, 9.54. Found: C, 63.93;
H, 9.47.
[4,6-Di-O-(tert-butyldimethylsilyl)-2,3-dideoxy- -D-erythro-hex-2-enopyrano-
syl]-4-methoxymethoxybenzene (2c): yield 80%; oil; Rf 0.40 (petroleum ether/ethyl
20
1
acetate 10/1); [a]D + 160 (c 1.0, CH3OH); H NMR (200 MHz, CDCl3) d 0.05 (s, 6H,
SiCH3), 0.15 (s, 3H, SiCH3), 0.16 (s, 3H, SiCH3), 0.91 (s, 9H, SiCMe3), 0.95 (s, 9H,
SiCMe3), 3.49 (s, 3H, OCH3), 3;52 (m, 1H, H-5), 3.83 (dd, 1H, J6a,6b = 11.3,
J6a,5 = 4.7 Hz, 1H, H-6a), 3.95 (dd, 1H, J6b,6a = 11.3, J6b,5 = 1.7 Hz, H-6b), 4.38 (dd,
1H, J4,5 = 8.4, J4,1 = 2.6 Hz, H-4), 5.12 (d, 1H, J1,4 = 2.6 Hz, H-1), 5.18 (s, 2H,
OCH2O), 5.72 (d, 1H, J2,3 = 10.9 Hz, H-2), 5.82 (d, 1H, J3,2 = 10.9 Hz, H-3), 7.01 (d,
2H, JH,H = 8.6 Hz, Harom), 7.27 (d, 2H, JH,H = 8.6 Hz, Harom); 13C (50 MHz, CDCl3)
d ꢀ4.5, ꢀ4.4, ꢀ4.1, ꢀ3.6, 18.7, 19.1, 26.8, 26.6, 56.6, 63.6, 64.3, 78.3, 81.4, 95.2,
116.7, 128.9, 130.4, 131.3, 135.5, 157.5.
Anal. Calcd for C26H46O5Si2 (494.82): C, 63.11; H, 9.37. Found: C, 63.53; H, 9.56.
[4,6-Di-O-(tert-butyldimethylsilyl)-2,3-dideoxy- -D-erythro-hex-2-enopyrano-
syl]-4-dimethylaminobenzene (2d): yield 80%; oil; Rf 0.21 (petroleum ether/
20
1
dichloromethane 1/1); [a]D + 179.8 (c 1.2, CH2Cl2); H NMR (200 MHz, CDCl3)
d 0.02 (s, 6H, SiCH3), 0.12 (s, 3H, SiCH3), 0.13 (s, 3H, SiCH3), 0.88 (s, 9H, SiCMe3),

Enantiopure Trioxadecalin Derived Liquid Crystals
693
0.92 (s, 9H, SiCMe3), 3.48 (ddd, 1H, J5,4 = 8.8, J5,6a = 4.8, J5,6a = 2.2 Hz, H-5), 3.80
(dd, 1H, J6a,6b = 11.8, J6a,5 = 4.8 Hz, H-6a), 3.90 (dd, 1H, J6b,6a = 11.8, J6b,5 = 2.2 Hz,
H-6b), 4.33 (dd, 1H, J4,5 = 8.8, J4,1 = 2.6 Hz, H-4), 5.06 (d, 1H, J1,4 = 2.6 Hz, H-1),
5.75 (bs, 2H, H-2, H-3), 6.70 (d, 2H, JH,H = 8.6 Hz, Harom), 7.19 (d, 2H, JH,H = 8.6 Hz,
H
arom); 13C (50 MHz, CDCl3) d ꢀ4.9, ꢀ4.8, ꢀ4.5, ꢀ4.0, 18.2, 18.7, 26.2, 26.3, 41.0,
63.5, 64.2, 77.3, 81.0, 113.1, 126.3, 129.7, 131.3, 142.7, 150.5.
Anal. Calcd for C26H47NO3Si2 (477.84); C, 65.35; H, 9.91. Found: C, 64.86;
H, 9.71.
Standard procedure for the preparation of unsaturated C-arylglycosides 3.
The unsaturated C-aryl glycoside 2 (0.43 mmol) was stirred in THF (5 mL) at rt in the
presence of tetrabutylammonium fluoride trihydrate (139 mg, 0.44 mmol). After 2 h,
the solvent was evaporated, and the crude residue treated with CH2Cl2 (25 mL) and
H2O (5 mL). Evaporation of the organic solvent gave quantitatively the crude diol 4
which was purified by flash-chromatography on silica.
(2,3-Dideoxy- -D-erythro-hex-2-enopyranosyl)-4-hydroxybenzene (3a): yield
20
80%; oil; Rf 0.2 (petroleum ether/ethyl acetate 1/4); [a]D + 211.0 (c 0.9, CH3OH);
1H NMR (200 MHz, CD3OH) d 3.53 (ddd, 1H, J5,4 = 8.8, J5,6a = 6.5, J5,6b = 2.2 Hz,
H-5), 3.67 (dd, 1H, J6a,6b = 11.8, J6a,5 = 6.5 Hz, H-6a), 3.89 (dd, 1H, J6b,6a = 11.8,
J6b,5 = 2.2 Hz, H-6b), 4.11 (dm, 1H, J4,5 = 8.8 Hz, H-4), 5.06 (bs, 1H, H-1), 5.79 (dm,
1H, J2,3 = 11.5 Hz, H-2), 5.86 (dm, 1H, J3,2 = 11.5 Hz, H-3), 6.73 (d, 2H, JH,H = 6.6
Hz, Harom), 7.06 (d, 2H, JH,H = 6.6 Hz, Harom); 13C (50 MHz, CDCl3) d 61.5, 62.3,
76.0, 81.0, 114.8, 128.5, 130.1, 130.2, 131.5, 156.9. HRMS: Calcd for C12H15O4 (CI)
[M + H]+m/z 223.0970. Found: 223.0969.
(2,3-Dideoxy- -D-erythro-hex-2-enopyranosyl)-4-methoxybenzene (3b): yield
20
80%; oil; Rf 0.35 (petroleum ether/ethyl acetate 1/4); [a]D + 241.8 (c 0.6, CH3OH);
1H NMR (200 MHz, CDCl3) d 2.04 (bs, 2H, 2 ꢁ OH), 3.58 (ddd, 1H, J5,4 = 9.2,
J5,6a = 5.5, J5,6b = 4.1 Hz, H-5), 3.80 (s, 3H, OCH3), 3.84 (dd, 1H, J6a,6b = 11.8,
J6a,5 = 5.5 Hz, H-6a), 3.94 (dd, 1H, J6b,6a = 11.8, J6b,5 = 4.1 Hz, H-6b), 4.33 (dm, 1H,
J4,5 = 9.2 Hz, H-4), 5.10 (bs, 1H, H-1), 5.83 (dm, 1H, J2,3 = 9.9 Hz, H-2), 5.93 (dm,
J3,2 = 9.9 Hz, H-3), 6.88 (d, 2H, JH,H = 8.1 Hz, Harom), 7.24 (d, 2H, JH,H = 8.1 Hz,
H
132.5, 134.7, 161.2.
Anal. Calcd for C13H16O4 (236.27): C, 66.09; H, 6.83. Found: C, 65.92; H, 6.95.
arom); 13C (50 MHz, CD3OD) d 56.0, 63.8, 64.6, 78.6, 82.4, 115.0, 130.1, 130.7,
(2,3-Dideoxy- -D-erythro-hex-2-enopyranosyl)-4-methoxymethoxybenzene (3c):
20
yield 90%; oil; Rf 0.30 (petroleum ether/ethyl acetate 1/4); [a]D + 164.5 (c 1.2,
1
CHCl3); H NMR (200 MHz, CDCl3) d 1.70–1.90 (m, 2H, 2 ꢁ OH), 3.46 (s, 3H,
OCH3), 3.57 (ddd, 1H, J5,4 = 8.8, J5,6a = 5.3, J5,6b = 4.1 Hz, H-5), 3.83 (dd, 1H,
J6a,6b = 11.6, J6a,5 = 5.3 Hz, H-6a), 3.94 (dd, 1H, J6b,6a = 11.6, J6b,5 = 4.1 Hz, H-6b),
4.32 (dm, 1H, J4,5 = 8.8 Hz, H-4), 5.13 (bs, 1H, H-1), 5.17 (s, 2H, OCH2O), 5.82 (dm,
1H, J2,3 = 10.2 Hz, H-2), 5.92 (dm, 1H, J3,2 = 10.2 Hz, H-3), 7.02 (d, 2H, JH,H = 8.7
Hz, Harom), 7.25 (d, 2H, JH,H = 8.7 Hz, Harom); 13C (50 MHz, CDCl3) d 56.0, 63.3,
64.4, 77.0, 79.5, 94.5, 116.4, 128.8, 129.1, 131.2, 133.8, 157.3.
Anal. Calcd for C14H18O5 (266.30): C, 63.15; H, 6.81. Found: C, 62.71; H, 6.82.

694
Bertini et al.
(2,3-Dideoxy- -D-erythro-hex-2-enopyranosyl)-4-dimethylaminobenzene (3d):
20
yield 80%; oil; Rf 0.22 (petroleum ether/ethyl acetate 1/5); [a]D + 219.0 (c 1.2,
1
CHCl3); H NMR (300 MHz, CDCl3) d 1.88 (s, 1H, OH), 2.13 (s, 1H, OH), 2.95 (s,
6H, CH3), 3.56 (ddd, 1H, J5,4 = 8.8, J5,6a = 5.5, J5,6b = 4.0 Hz, H-5), 3.82 (dd, 1H,
J6a,6b = 11.4, J6a,5 = 5.5 Hz, H-6a), 3.93 (dd, 1H, J6b,6a = 11.4, J6b,5 = 4.0 Hz, H-6b),
4.32 (bd, 1H, J4,5 = 8.8 Hz, H-4), 5.08 (bs, 1H, H-1), 5.84 (bd, 1H, J2,3 = 10.3 Hz,
H-2), 5.91 (bd, 1H, J3,2 = 10.3 Hz, H-3), 6.71 (d, 2H, JH,H = 8.8 Hz, Harom), 7.19 (d,
2H, JH,H = 8.8 Hz, Harom); 13C (50 MHz, CDCl3) d 40.7, 63.1, 64.2, 77.2, 112.6,
128.8, 128.2, 128.6, 129.0, 131.3, 150.6.
Anal. Calcd for C14H19NO3 (249.31): C, 67.45; H, 7.68. Found: C, 67.64; H, 7.67.
Standard procedure for the preparation of saturated C-arylglycosides 4. The
unsaturated diol 3 was dissolved in ethanol (5 mL), and treated with molecular
hydrogen at atmospheric pressure and room temperature in the presence of
[Rh(COD)(dppb)]ClO4 (0.02 mmol). After 24 h, filtration of the mixture and evapo-
ration of the solvent gave a residue, which was purified by column chromatography to
afford the saturated C-aryl glycoside 4.
(2,3-Dideoxy- -D-erythro-hexanopyranosyl)-4-hydroxybenzene (4a): yield
20
65%; oil; Rf 0.20 (petroleum ether/ethyl acetate 1/4); [a]D + 56.9 (c 0.8, CH3OH);
1H NMR (200 MHz, CD3OD) d 1.72–1.92 (m, 2H, H-2ax, H-3ax), 2.07 (m, 1H, H-2eq),
2.34 (m, 1H, H-3eq), 3.49 (ddd, 1H, J5,4 = 9.5, J5,6a = 5.8, J5,6b = 2.4 Hz, H-5), 3.66
(dm, 1H, J4,5 = 9.5 Hz, H-4), 3.86 (dd, 1H, J6a,6b = 11.7, J6a,5 = 5.8 Hz, H-6a), 4.05
(dd, 1H, J6b,6a = 11.7, J6b,5 = 2.4 Hz, H-6b), 4.54 (dd, 1H, J1,2a = 10.2, J1,2eq = 2.1 Hz,
H-1), 6.90 (d, 2H, JH,H = 8.6 Hz, Harom), 7.38 (d, 2H, JH,H = 8.6 Hz, Harom); 13C (50
MHz, CD3OD) d 34.3, 63.9, 67.6, 80.8, 84.7, 116.1, 128.8, 128.4, 134.9, 158.0. HRMS:
Calcd for C12H17O4 (CI) [M + H]+m/z 225.1126. Found: 225.1129.
(2,3-Dideoxy- -D-erythro-hexanopyranosyl)-4-methoxybenzene (4b): yield
60%; oil; Rf 0.32 (petroleum ether/ethyl acetate 1/4); [a]D20 + 55.9 (c 0.6, CH2Cl2);
1H NMR (200 MHz, CDCl3) d 1.59–1.79 (m, 2H, H-2ax, H-3ax), 1.93 (m, 1H, H-2eq),
2.18-2.33 (m, 3H, H-3eq, OH), 3.39 (ddd, 1H, J5,4 = 9.2, J5,6a = 4.8, J5,6b = 4.4 Hz,
H-5), 3.68 (dm, 1H, J4,5 = 9.4 Hz, H-4), 3.79 (s, 3H, OCH3), 3.83 (dd, 1H,
J6a,6b = 11.8, J6a,5 = 4.8 Hz, H-6a), 3.91 (dd, 1H, J6b,6a = 11.8, J6b,5 = 4.4 Hz, H-6b),
4.36 (dd, 1H, J1,2ax = 8.2, J1,2eq = 2.3 Hz, H-1), 6.87 (d, 2H, JH,H = 8.8 Hz, Harom),
7.26 (d, 2H, JH,H = 8.8 Hz, Harom); 13C (50 MHz, CDCl3) d 32.9, 33.0, 55.4, 63.6,
67.4, 79.3, 82.0, 113.9, 127.5, 134.2, 159.3.
Anal. Calcd for C13H18O4 (238.29): C, 65.35; H, 7.61. Found: C, 64.90; H, 7.62.
(2,3-Dideoxy- -D-erythro-hexanopyranosyl)-4-methoxymethoxybenzene (4c):
20
yield 60%; oil; Rf 0.25 (petroleum ether/ethyl acetate 1/4); [a]D + 49.1 (c 1.1,
1
CH2Cl2); H NMR (200 MHz, CDCl3) d 1.58–1.76 (m, 2H, H-2ax, H-3ax), 1.96 (m, 1H,
H-2eq), 2.05–2.21 (m, 3H, H-3eq, OH), 3.39 (ddd, 1H, J5,4 = 9.2, J5,6a = 4.9, J5,6b = 4.3
Hz, H-5), 3.46 (s, 3H, OCH3), 3.66 (ddd, 1H, J4,3ax = 10.2, J4,5 = 9.2, J4,3eq = 4.8 Hz,
H-4), 3.81 (dd, 1H, J6a,6b = 11.6, J6a,5 = 4.9 Hz, H-6a), 3.89 (dd, 1H, J6b,6a = 11.6,
J6b,5 = 4.3 Hz, H-6b), 4.36 (dd, 1H, J1,2ax = 10.4, J1,2eq = 2.2 Hz, H-1), 5.16 (s, 2H,

Enantiopure Trioxadecalin Derived Liquid Crystals
695
OCH2O), 7.00 (d, 2H, JH,H = 8.7 Hz, Harom), 7.26 (d, 2H, JH,H = 8.7 Hz, Harom);
13C (50 MHz, CDCl3) d 32.8, 33.0, 56.0, 63.7, 67.6, 79.1, 81.8, 94.5, 116.2, 127.3,
135.3, 156.8.
Anal. Calcd for C14H20O5 (268.31): C, 62.67; H, 7.51. Found: C, 61.92; H, 7.43.
(2,3-Dideoxy- -D-erythro-hexanopyranosyl)-4-dimethylaminobenzene (4d):
20
yield 83%; oil; Rf 0.2 (petroleum ether/ethyl acetate 1/4); [a]D + 51.2 (c 0.7,
1
CH2Cl2); H NMR (300 MHz, CDCl3) d 1.66 (m, 1H, H-2ax), 1.78 (m, 1H, H-3ax),
1.92 (m, 1H, H-2eq), 2.12–2.32 (m, 3H, H-3eq, OH), 2.93 (s, 6H, NMe2), 3.40 (ddd,
1H, J5,4 = 9.2, J5,6a = 5.2, J5,6b = 4.1 Hz, H-5), 3.46, 3.68 (ddd, 1H, J4,3ax = 10.3,
J4,5 = 9.2, J4,3eq = 4.4 Hz, H-4), 3.81 (dd, 1H, J6a,6b = 11.6, J6a,5 = 5.2 Hz, H-6a), 3.90
(dd, 1H, J6b,6a = 11.6, J6b,5 = 4.4 Hz, H-6b), 4.34 (dd, 1H, J1,2ax = 11.0, J1,2eq = 2.2
Hz, H-1), 6.72 (d, 2H, JH,H = 8.6 Hz, Harom), 7.22 (d, 2H, JH,H = 8.6 Hz, Harom); 13C
(50 MHz, CDCl3) d 34.3, 34.4, 41.5, 64.0, 67.8, 81.1, 84.9, 114.2, 128.5, 132.4, 152.1.
Anal. Calcd for C14H21NO3 (251.33): C, 66.91; H, 8.42. Found: C, 66.58; H, 8.60.
Standard procedure for the preparation of compounds 5 7. A flask
ꢀ
containing 0.16 mmol of the diol 4, 0.22 mmol of 4-alkyloxybenzaldehyde dimethyl
acetal, and 5.0 mg of p-toluenesulfonic acid monohydrate, dissolved in 5 mL of N,N-
dimethylformamide, was connected to a rotatory evaporator. The mixture was heated at
reduced pressure (30 mbar) in a water-bath at 60°C, until TLC revealed that the
reaction was complete. The solvent was removed in vacuo (10 hPA) at 75°C. The solid
residue was washed with a saturated solution of sodium hydrogen carbonate, filtered,
washed with water and cold ethanol, and then recrystallized from ethanol to afford
compounds 5–7.
(1S,3R,6R,8R)-8-(4-Methoxyphenyl)-3-(4-octyloxyphenyl)-2,4,7-trioxabicy-
clo[4.4.0]decane (5d): yield 39%; mp 135.7°C; [a]D20 + 22.3 (c 0.5, CHCl3); 1H NMR
(400 MHz, C6D6) d 0.88 (t, 3H, JH,H = 6.6 Hz, CH3), 1.12–1.33 (m, 12H, CH2), 1.52–
1.72 (m, 5H, CH2, 2 ꢁ H-9, H-10), 1.98 (m, 1H, H-10), 3.28 (s, 3H, OCH3), 3.37 (ddd, 1H,
J1,6 = 10.2, J1,10ax = 9.7, J1,10eq = 4.1 Hz, H-1), 3.49 (ddd, 1H, J6,5a = 10.2, J6,1 = 9.7,
J6,5b = 4.6 Hz, H-6), 3.60 (t, 2H, JH,H = 6.1 Hz, OCH2), 3.69 (dd, 1H, J5a,5b = 10.2,
J5a,6 = 10.2 Hz, H-5a), 4.14 (bd, 1H, J8,9ax = 9.7 Hz, H-8), 4.31 (dd, 1H, J5b,5a = 10.2,
J5b,6 = 4.6 Hz, H-5b), 5.50 (s, 1H, H-3), 6.82 (d, 2H, JH,H = 8.6 Hz, 2 Harom), 6.89 (d,
2H, JH,H = 8.6 Hz, Harom), 7.19 (d, 2H, JH,H = 8.6 Hz, Harom), 7.66 (d, 2H, JH,H = 8.6
Hz, Harom); 13C (100 MHz, C6D6) d 14.3, 23.4, 26.8, 30.0, 30.1, 32.6, 34.2, 55.2, 68.3,
70.2, 74.9, 78.8, 79.4, 102.5, 114.3, 127.8, 128.5, 128.7, 131.7, 135.2, 160.0, 160.5.
Anal. Calcd for C28H38O5 (454.61): C, 73.98; H, 8.43. Found: C, 73.91; H, 8.45.
(1S,3R,6R,8R)-8-(4-Methoxymethoxyphenyl)-3-(4-methoxyphenyl)-2,4,7-trioxa-
bicyclo[4.4.0]decane (6a): yield 60%; mp 127.6°C; [a]D20 + 27.4 (c 0.2, CHCl3); H
1
NMR (400 MHz, C6D6) d 1.48–1.72 (m, 3H, 2 ꢁ H-9, H-10), 1.96 (m, 1H, H-10),
3.12 (s, 3H, OCH3), 3.38 (m, 1H, H-1), 3.50 (ddd, 1H, J6,5a = 10.2, J6,1 = 9.6,
J6,5b = 4.6 Hz, H-6), 3.69 (dd, 1H, J5a,5b = 10.2, J5a,6 = 10.2 Hz, H-5a), 4.14 (bd, 1H,
J8,9ax = 10.7 Hz, H-8), 4.31 (dd, 1H, J5b,5a = 10.2, J5b,6 = 4.6 Hz, H-5b), 4.85 (s, 2H,
OCH2O), 5.51 (s, 1H, H-3), 6.88 (d, 2H, JH,H = 8.1 Hz, Harom), 7.06–7.30 (m, 4H,

696
Bertini et al.
Harom), 7.64 (d, 2H, JH,H = 8.1 Hz, Harom); 13C (100 MHz, C6D6) d 29.9, 34.1, 55.8,
67.9, 70.2, 74.9, 78.8, 79.8, 94.4, 102.5, 114.3, 114.7, 127.8, 128.5, 128.7, 131.6, 136.0,
160.0, 160.5.
Anal. Calcd for C22H26O6 (386.45): C, 68.38; H, 6.78. Found: C, 68.01; H, 6.77.
(1S,3R,6R,8R)-3-(4-Butyloxyphenyl)-8-(4-methoxymethoxyphenyl)-2,4,7-trioxa-
20
1
bicyclo[4.4.0]decane (6b): yield 45%; mp 142.0°C; [a]D + 23.4 (c 0.3, CHCl3); H
NMR (400 MHz, C6D6) d 0.81 (t, 3H, JH,H = 7.1 Hz, CH3), 1.28 (m, 2H, CH2), 1.45–
1.71 (m, 5H, CH2, 2 ꢁ H-9, H-10), 1.96 (m, 1H, H-10), 3.12 (s, 3H, OCH3), 3.38 (m,
1H, H-1), 3.50 (ddd, 1H, J6,5a = 10.2, J6,1 = 9.6, J6,5b = 4.6 Hz, H-6), 3.55 (t, 2H,
JH,H = 6.1 Hz, OCH2), 3.69 (dd, 1H, J5a,5b = 10.2, J5a,6 = 10.2 Hz, H-5a), 4.14 (bd,
1H, J8,9ax = 10.7 Hz, H-8), 4.31 (dd, 1H, J5b,5a = 10.2, J5b,6 = 4.6 Hz, H-5b), 4.85 (s,
2H, OCH2O), 5.50 (s, 1H, H-3), 6.89 (d, 2H, JH,H = 8.1 Hz, Harom), 7.08–7.28 (m, 4H,
H
30.1, 32.0, 34.2, 55.8, 67.9, 70.2, 74.9, 78.8, 79.8, 94.4, 102.5, 114.3, 114.7, 127.8,
arom), 7.65 (d, 2H, JH,H = 8.1 Hz, Harom); 13C (100 MHz, C6D6) d 14.3, 19.9, 25.3,
128.5, 128.7, 131.6, 136.0, 160.0, 160.5.
Anal. Calcd for C25H32O6 (428.53): C, 70.07; H, 7.53. Found: C, 69.85; H, 7.49.
(1S,3R,6R,8R)-3-(4-Hexyloxyphenyl)-8-(methoxymethoxyphenyl)-2,4,7-trioxabi-
20
1
cyclo[4.4.0]decane (6c): yield 50%; mp 133.5°C; [a]D + 22.8 (c 0.3, CHCl3); H
NMR (400 MHz, C6D6) d 0.82 (t, 3H, JH,H = 6.1 Hz, CH3), 1.10-1.31 (m, 6H, CH2),
1.48–1.68 (m, 5H, CH2, 2 ꢁ H-9, H-10), 1.93 (m, 1H, H-10), 3.09 (s, 3H, OCH3),
3.34 (ddd, 1H, J1,6 = 10.2, J1,10ax = 9.7, J1,10eq = 4.1 Hz, H-1), 3.44 (ddd, 1H,
J6,5a = 10.2, J6,1 = 9.7, J6,5b = 4.6 Hz, H-6), 3.55 (t, 2H, JH,H = 6.1 Hz, OCH2), 3.64
(dd, 1H, J5a,5b = 10.2, J5a,6 = 10.2 Hz, H-5a), 4.11 (bd, 1H, J8,9ax = 9.2 Hz, H-8), 4.28
(dd, 1H, J5b,5a = 10.2, J5b,6 = 4.6 Hz, H-5b), 4.84 (s, 2H, OCH2O), 5.50 (s, 1H, H-3),
6.92 (d, 2H, JH,H = 8.1 Hz, Harom), 7.05–7.21 (m, 4H, Harom), 7.64 (d, 2H, JH,H = 8.1
Hz, Harom); 13C (100 MHz, C6D6) d 14.6, 23.3, 26.4, 29.9, 30.0, 32.3, 34.2, 55.9, 68.3,
70.1, 74.9, 78.8, 79.7, 94.9, 102.5, 114.7, 116.7, 127.8, 128.5, 128.7, 131.6, 136.4,
157.7, 160.5.
Anal. Calcd for C27H36O6 (456.58): C, 71.03; H, 7.95. Found: C, 70.75; H, 7.77.
(1S,3R,6R,8R)-8-(4-Methoxymethoxyphenyl)-3-(4-octyloxyphenyl)-2,4,7-trioxa-
20
1
bicyclo[4.4.0]decane (6d): yield 61%; mp 124.7°C; [a]D + 19.5 (c 0.2, CHCl3); H
NMR (400 MHz, C6D6) d 0.90 (t, 3H, JH,H = 6.6 Hz, CH3), 1.12-1.36 (m, 12H, CH2),
1.46–1.72 (m, 5H, CH2, 2 ꢁ H-9, H-10), 1.96 (m, 1H, H-10), 3.11 (s, 3H, OCH3), 3.36
(m, 1H, H-1), 3.44 (ddd, 1H, J6,5a = 10.2, J6,1 = 9.2, J6,5b = 4.6 Hz, H-6), 3.55 (t, 2H,
JH,H = 6.1 Hz, OCH2), 3.64 (dd, 1H, J5a,5b = 10.2, J5a,6 = 10.2 Hz, H-5a), 4.14 (bd,
1H, J8,9ax = 9.7 Hz, H-8), 4.31 (dd, 1H, J5b,5a = 10.2, J5b,6 = 4.6 Hz, H-5b), 5.50 (s,
1H, H-3), 6.91 (d, 2H, JH,H = 7.1 Hz, Harom), 7.05–7.18 (m, 4H, Harom), 7.66 (d, 2H,
JH,H = 7.1 Hz, Harom); 13C (100 MHz, C6D6) d 14.3, 23.4, 26.8, 30.0, 30.1, 32.6, 34.2,
55.8, 68.3, 70.2, 74.9, 78.8, 79.8, 94.9, 102.5, 114.7, 116.7, 127.8, 128.5, 128.7, 131.6,
136.0, 160.0, 160.5.
Anal. Calcd for C29H40O6 (484.64): C, 71.87; H, 8.32. Found: C, 71.36; H, 8.28.
(1S,3R,6R,8R)-8-(4-Dimethylaminophenyl)-3-(4-methoxyphenyl)-2,4,7-trioxabi-
20
1
cyclo[4.4.0]decane (7a): yield 46%; mp 184.8°C; [a]D + 27.8 (c 0.3, CHCl3); H

Enantiopure Trioxadecalin Derived Liquid Crystals
697
NMR (400 MHz, C6D6) d 1.69–1.80 (m, 3H, 2 ꢁ H-9, H-10), 2.03 (m, 1H, H-10),
2.52 (s, 6H, NMe2), 3.26 (s, 3H, OCH3), 3.45 (m, 1H, H-1), 3.57 (ddd, 1H,
J6,5a = 10.2, J6,1 = 9.2, J6,5b = 4.6 Hz, H-6), 3.74 (dd, 1H, J5a,5b = 10.2, J5a,6 = 10.2
Hz, H-5a), 4.27 (bd, 1H, J8,9ax = 10.7 Hz, H-8), 4.35 (dd, 1H, J5b,5a = 10.2, J5b,6 = 4.6
Hz, H-5b), 5.51 (s, 1H, H-3), 6.68 (d, 2H, JH,H = 8.6 Hz, Harom), 6.82 (d, 2H,
JH,H = 8.6 Hz, Harom), 7.30 (d, 2H, JH,H = 8.6 Hz, Harom), 7.65 (d, 2H, JH,H = 8.6 Hz,
H
114.1, 127.6, 128.5, 128.7, 131.1, 131.9, 150.9, 160.8.
Anal. Calcd for C22H27NO4 (369.46): C, 71.52; H, 7.37. Found: C, 71.15; H, 7.11.
arom); 13C (100 MHz, C6D6) d 30.2, 34.1, 40.7, 55.1, 70.3, 75.0, 79.0, 80.3, 102.4,
(1S,3R,6R,8R)-3-(4-Butyloxyphenyl)-8-(4-dimethylaminophenyl)-2,4,7-trioxabi-
1
cyclo[4.4.0]decane (7b): yield 53%; mp 155.9°C; [a]D20 + 26.0 (c 0.4, CHCl3); H
NMR (400 MHz, C6D6) d 0.78 (t, 3H, JH,H = 7.1 Hz, CH3), 1.28 (m, 2H, CH2), 1.50
(m, 2H, CH2), 1.66–1.71 (m, 3H, 2 ꢁ H-9, H-10), 1.99 (m, 1H, H-10), 2.49 (s, 6H,
NMe2), 3.41 (m, 1H, H-1), 3.50–3.59 (m, 3H, H-6, OCH2), 3.72 (dd, 1H, J5a,5b = 10.2,
J5a,6 = 10.2 Hz, H-5a), 4.24 (bd, 1H, J8,9ax = 10.7 Hz, H-8), 4.31 (dd, 1H, J5b,5a = 10.2,
J5b,6 = 4.6 Hz, H-5b), 5.50 (s, 1H, H-3), 6.63 (d, 2H, JH,H = 8.1 Hz, Harom), 6.88 (d,
2H, JH,H = 7.6 Hz, Harom), 7.28 (d, 2H, JH,H = 8.1 Hz, Harom), 7.64 (d, 2H, JH,H = 7.6
Hz, Harom); 13C (100 MHz, C6D6) d 14.3, 19.9, 30.2, 32.0, 34.1, 40.2, 67.9, 70.3, 75.0,
79.0, 80.3, 102.5, 113.7, 114.7, 127.8, 128.5, 128.7, 131.6, 136.0, 150.4, 160.5.
Anal. Calcd for C25H33NO4 (411.55): C, 72.96; H, 8.08. Found: C, 72.56; H, 8.07.
(1S,3R,6R,8R)-8-(4-Dimethylaminophenyl)-3-(4-hexyloxyphenyl)-2,4,7-trioxabi-
20
1
cyclo[4.4.0]decane (7c): yield 49%; mp 158.9°C; [a]D + 25.5 (c 0.2, CHCl3); H
NMR (400 MHz, C6D6) d 0.84 (t, 3H, JH,H = 7.1 Hz, CH3), 1.12–1.36 (m, 6H, CH2),
1.51–1.59 (m, 2H, H-9, H-10), 1.66–1.77 (m, 3H, H-9, CH2), 2.00 (m, 1H, H-10), 2.51
(s, 6H, NMe2), 3.45 (m, 1H, H-1), 3.52–3.62 (m, 3H, H-6, OCH2), 3.72 (dd, 1H,
J5a,5b = 10.2, J5a,6 = 10.2 Hz, H-5a), 4.26 (bd, 1H, J8,9ax = 9.7 Hz, H-8), 4.38 (dd, 1H,
J5b,5a = 10.2, J5b,6 = 4.6 Hz, H-5b), 5.50 (s, 1H, H-3), 6.64 (d, 2H, JH,H = 8.1 Hz,
H
arom), 6.90 (d, 2H, JH,H = 8.1 Hz, Harom), 7.30 (d, 2H, JH,H = 8.1 Hz, Harom), 7.66 (d,
2H, JH,H = 8.1 Hz, Harom); 13C (100 MHz, C6D6) d 14.6, 23.3, 26.4, 29.9, 30.2, 32.3,
34.1, 40.7, 68.3, 70.3, 75.0, 79.0, 80.3, 102.4, 113.1, 114.7, 127.6, 128.5, 128.7, 131.1,
131.8, 150.9, 160.4.
Anal. Calcd for C27H37NO4 (439.60): C, 73.77; H, 8.48. Found: C, 73.56; H, 8.56.
(1S,3R,6R,8R)-8-(4-Dimethylaminophenyl)-3-(4-octyloxyphenyl)-2,4,7-trioxabi-
20
cyclo[4.4.0]decane (7d): yield 64%; mp 144.7°C; [a]D + 23.1 (c 0.3, CHCl3); 1H
NMR (400 MHz, C6D6) d 0.96 (t, 3H, JH,H = 6.6 Hz, CH3), 1.21–1.41 (m, 12H, CH2),
1.58–1.68 (m, 2H, H-9, H-10), 1.72–1.82 (m, 3H, H-9, CH2), 2.08 (m, 1H, H-10), 2.58
(s, 6H, NMe2), 3.50 (m, 1H, H-1), 3.58–3.70 (m, 3H, H-6, OCH2), 3.79 (dd, 1H,
J5a,5b = 10.2, J5a,6 = 10.2 Hz, H-5a), 4.32 (bd, 1H, J8,9ax = 8.1 Hz, H-8), 4.38 (dd, 1H,
J5b,5a = 10.2, J5b,6 = 4.6 Hz, H-5b), 5.57 (s, 1H, H-3), 6.70 (d, 2H, JH,H = 8.1 Hz,
H
arom), 6.97 (d, 2H, JH,H = 8.1 Hz, Harom), 7.36 (d, 2H, JH,H = 8.1 Hz, Harom), 7.74 (d,
2H, JH,H = 8.1 Hz, Harom); 13C (100 MHz, C6D6) d 14.7, 23.5, 26.7, 30.0, 30.1, 30.2,
32.6, 34.2, 40.7, 68.3, 70.3, 75.0, 79.0, 80.3, 102.5, 113.1, 114.7, 127.6, 128.6, 128.7,
131.1, 131.8, 150.9, 160.4.
Anal. Calcd for C29H41NO4 (467.65): C, 74.48; H, 8.84. Found: C, 73.98; H, 8.72.

698
Bertini et al.
Standard procedure for the preparation of compounds 8–11. A solution of
0.14 mmol of compound 4 and 0.17 mmol of 4-alkyloxyphenyl boronic acid in 5 mL
toluene was stirred at 45°C under 60 mbar. The water produced in the reaction was
co-evaporated three times with 5 mL of toluene. The remaining crystalline solid was
recrystallized from ethanol to give compounds 8–11.
(1S,6R,8R)-8-(4-Hydroxyphenyl)-3-(4-methoxyphenyl)-2,4,7-trioxa-3-borabicy-
clo[4.4.0]decane (8a): yield 50%; mp 180.3°C; [a]D20 + 29.7 (c 0.1, CHCl3); 1H
NMR (300 MHz, CDCl3) d 1.68–1.92 (m, 2H, H-9), 2.04 (m, 1H, H-10), 2.37 (m, 1H,
H-10), 3.58–3.88 (m, 6H, H-1, H-6, OCH3, OH), 3.94 (dd, 1H, J5a,5b = 10.3,
J5a,6 = 10.3 Hz, H-5a), 4.24 (dd, 1H, J5b,5a = 10.3, J5b,6 = 5.1 Hz, H-5b), 4.48 (bd, 1H,
J8,9ax = 8.8 Hz, H-8), 6.79 (d, 2H, JH,H = 8.6 Hz, Harom), 6.87 (d, 2H, JH,H = 8.6 Hz,
H
arom), 7.23 (d, 2H, JH,H = 8.6 Hz, Harom), 7.74 (d, 2H, JH,H = 8.6 Hz, Harom); 13C (75
MHz, CDCl3) d 31.2, 32.9, 55.1, 64.9, 71.6, 76.1, 79.8, 113.2, 113.9, 127.4, 127.3,
135.8, 155.6, 161.9.
Anal. Calcd for C19H21BO4 (324.19): C, 70.39; H, 6.53. Found: C, 70.24; H, 6.34.
(1S,6R,8R)-3-(4-Hexyloxyphenyl)-8-(4-hydroxyphenyl)-2,4,7-trioxa-3-borabicy-
20
1
clo[4.4.0]decane (8c): yield 62%; mp 80.9°C; [a]D + 24.5 (c 0.1, CHCl3); H NMR
(300 MHz, CDCl3) d 0.90 (t, 3H, JH,H = 6.1 Hz, CH3), 1.30–1.37 (m, 4H, CH2), 1.45
(m, 2H, CH2), 1.72–1.92 (m, 4H, H-9, CH2), 2.04 (m, 1H, H-10), 2.38 (m, 1H, H-10),
3.63 (ddd, 1H, J6,5a = 10.3, J6,1 = 9.2, J6,5b = 5.1 Hz, H-6), 3.81 (s, 3H, OCH3), 3.84–
4.01 (m, 4H, H-1, H-5a, OCH2), 4.25 (dd, 1H, J5b,5a = 10.3, J5b,6 = 5.1 Hz, H-5b), 4.49
(dd, 1H, J8,9ax = 9.9, 1.4 Hz, H-8), 6.87 (d, 2H, JH,H = 8.4 Hz, Harom), 6.89 (d, 2H,
JH,H = 8.8 Hz, Harom), 7.28 (d, 2H, JH,H = 8.8 Hz, Harom), 7.74 (d, 2H, JH,H = 8.4 Hz,
Harom); 13C (75 MHz, CDCl3) d 14.1, 26.1, 29.3, 31.1, 31.8, 32.9, 55.3, 64.9, 67.8,
71.5, 76.0, 79.8, 113.8, 127.3, 127.9, 133.6, 135.7, 155.6, 161.5.
Anal. Calcd for C24H31BO4 (394.32): C, 73.10; H, 7.92. Found: C, 72.74; H, 7.92.
(1S,6R,8R)-8-(4-Hydroxyphenyl)-3-(4-octyloxyphenyl)-2,4,7-trioxa-3-borabicy-
20
1
clo[4.4.0]decane (8d): yield 30%; [a]D + 22.3 (c 0.7, CHCl3); H NMR (400 MHz,
CDCl3) d 0.88 (t, 3H, JH,H = 6.8 Hz, CH3), 1.23–1.28 (m, 8H, CH2), 1.45 (m, 2H,
CH2), 1.71–1.88 (m, 4H, H-9, CH2), 2.03 (m, 1H, H-10), 2.37 (m, 1H, H-10), 3.61
(ddd, 1H, J6,5a = 10.2, J6,1 = 9.2, J6,5b = 5.1 Hz, H-6), 3.87 (ddd, 1H, J1,10ax = 10.7,
J1,6 = 9.2, J1,10eq = 4.6 Hz, H-1), 3.94 (dd, 1H, J5a,5b = 10.2, J5a,6 = 10.2 Hz, H-5a),
3.97 (t, 2H, JH,H = 6.6 Hz, OCH2), 4.24 (dd, 1H, J5b,5a = 10.2, J5b,6 = 5.1 Hz, H-5b),
4.47 (dd, 1H, J8,9ax = 10.7, J8,9eq = 2.0 Hz, H-8), 6.79 (d, 2H, JH,H = 8.6 Hz, Harom),
6.87 (d, 2H, JH,H = 8.6 Hz, Harom), 7.23 (d, 2H, JH,H = 8.6 Hz, Harom), 7.74 (d, 2H,
JH,H = 8.5 Hz, Harom); 13C (50 MHz, CDCl3) d 14.5, 23.1, 26.5, 29.6, 29.7, 29.8,
31.5, 32.2, 32.3, 65.3, 68.2, 72.0, 76.5, 80.2, 114.2, 115.7, 127.9, 134.2, 136.2,
155.6, 161.9.
Anal. Calcd for C26H35BO4 (422.38): C, 73.94; H, 8.35. Found: C, 73.59; H, 8.35.
(1S,6R,8R)-8-(4-Methoxyphenyl)-3-(4-methoxyphenyl)-2,4,7-trioxa-3-borabicy-
clo[4.4.0]decane (9a): yield 60%; mp 158.0°C; [a]D + 29.0 (c 1.0, CHCl3); 1H
20
NMR (300 MHz, CDCl3) d 1.68–1.92 (m, 2H, H-9), 2.07 (m, 1H, H-10), 2.37 (m, 1H,
H-10), 3.58–3.88 (m, 8H, H-1, H-6, OCH3), 3.94 (dd, 1H, J5a,5b = 10.3, J5a,6 = 10.3

Enantiopure Trioxadecalin Derived Liquid Crystals
699
Hz, H-5a), 4.24 (dd, 1H, J5b,5a = 10.3, J5b,6 = 5.1 Hz, H-5b), 4.48 (bd, 1H, J8,9a = 8.8
Hz, H-8), 6.89 (d, 4H, JH,H = 8.5 Hz, Harom), 7.29 (d, 2H, JH,H = 8.6 Hz, Harom), 7.75
(d, 2H, JH,H = 8.6 Hz, Harom); 13C (75 MHz, CDCl3) d 31.2, 32.9, 55.1, 55.4, 64.9,
71.6, 76.1, 79.8, 113.2, 113.9, 127.3, 127.4, 135.8, 159.3, 161.9.
Anal. Calcd for C20H23BO5 (354.21): C, 67.82; H, 6.54. Found: C, 67.53; H, 6.49.
(1S,6R,8R)-3-(4-Butyloxyphenyl)-8-(4-methoxyphenyl)-2,4,7-trioxa-3-borabicy-
20
clo[4.4.0]decane (9b): yield 74%; mp 116.3°C; [a]D + 24.5 (c 0.9, CHCl3); 1H
NMR (400 MHz, CDCl3) d 0.96 (t, 3H, JH,H = 7.6 Hz, CH3), 1.49 (m, 2H, CH2), 1.70–
1.90 (m, 4H, H-9, CH2), 2.03 (m, 1H, H-10), 2.38 (m, 1H, H-10), 3.61 (ddd, 1H,
J6,5a = 10.2, J6,1 = 9.2, J6,5b = 5.1 Hz, H-6), 3.81 (s, 3H, OCH3), 3.84–4.02 (m, 4H,
H-1, H-5a, OCH2), 4.23 (dd, 1H, J5b,5a = 10.2, J5b,6 = 5.1 Hz, H-5b), 4.48 (dd, 1H,
J8,9ax = 11.2, J8,9eq = 2.0 Hz, H-8), 6.87 (m, 4H, Harom), 7.28 (d, 2H, JH,H = 8.6 Hz,
H
31.1, 31.3, 32.8, 55.3, 64.9, 67.4, 71.5, 76.0, 79.8, 113.7, 113.8, 127.3, 133.6, 135.7,
159.2, 161.5.
arom), 7.74 (d, 2H, JH,H = 8.6 Hz, Harom); 13C (100 MHz, CDCl3) d 13.9, 19.2,
Anal. Calcd for C23H29BO5 (396.29): C, 69.71; H, 7.38. Found: C, 69.42; H, 7.46.
(1S,6R,8R)-3-(4-Hexyloxyphenyl)-8-(4-methoxyphenyl)-2,4,7-trioxa-3-borabicy-
1
clo[4.4.0]decane (9c): yield 60%; mp 92.9°C; [a]D20 + 23.5 (c 0.1, CHCl3); H NMR
(300 MHz, CDCl3) d 0.90 (t, 3H, JH,H = 6.1 Hz, 3H, CH3), 1.30–1.37 (m, 4H, CH2),
1.45 (m, 2H, CH2), 1.72–1.92 (m, 4H, H-9, CH2), 2.04 (m, 1H, H-10), 2.38 (m, 1H, H-
10), 3.62 (ddd, 1H, J6,5a = 10.3, J6,1 = 9.2, J6,5b = 5.1 Hz, H-6), 3.80 (s, 3H, OCH3),
3.83–4.02 (m, 4H, H-1, H-5a, OCH2), 4.24 (dd, 1H, J5b,5a = 10.3, J5b,6 = 5.1 Hz, H-
5b), 4.51 (bd, 1H, J8,9ax = 11.0 Hz, H-8), 6.87 (d, 2H, JH,H = 8.5 Hz, Harom), 6.88 (d,
2H, JH,H = 8.8 Hz, Harom), 7.27 (d, 2H, JH,H = 8.5 Hz, Harom), 7.74 (d, 2H, JH,H = 8.8
Hz, Harom); 13C (75 MHz, CDCl3) d 14.1, 22.7, 26.1, 29.3, 31.1, 31.8, 32.9, 55.3, 64.9,
67.8, 71.5, 76.0, 79.8, 113.7, 113.8, 127.3, 133.6, 135.7, 159.3, 161.5.
Anal. Calcd for C25H33BO5 (424.24): C, 70.76; H, 7.84. Found: C, 70.26; H, 7.75.
(1S,6R,8R)-8-(4-Methoxyphenyl)-3-(4-octyloxyphenyl)-2,4,7-trioxa-3-borabicy-
clo[4.4.0]decane (9d): yield 63%; mp 90.1°C; [a]D20 + 21.0 (c 0.1, CHCl3); H NMR
1
(300 MHz, CDCl3) d 0.89 (t, 3H, JH,H = 7.0 Hz, CH3), 1.25–1.39 (m, 8H, CH2), 1.45
(m, 2H, CH2), 1.72–1.92 (m, 4H, H-9, H-10, CH2), 2.04 (m, 1H, H-9), 2.38 (m, 1H, H-
10), 3.61 (ddd, 1H, J6,5a = 10.2, J6,1 = 9.2, J6,5b = 5.1 Hz, H-6), 3.87 (ddd, 1H,
J1,10ax = 10.7, J1,6 = 9.2, J1,10eq = 4.6 Hz, H-1), 3.94 (dd, 1H, J5a,5b = 10.2, J5a,6 = 10.2
Hz, H-5a), 3.97 (t, 2H, JH,H = 6.6 Hz, OCH2), 4.24 (dd, 1H, J5b,5a = 10.2, J5b,6 = 5.1
Hz, H-5b), 4.47 (dd, 1H, J8,9ax = 10.7, J8,9eq = 2.0 Hz, H-8), 6.79 (d, 2H, JH,H = 8.6
Hz, Harom), 6.87 (d, 2H, JH,H = 8.6 Hz, Harom), 7.23 (d, 2H, JH,H = 8.6 Hz, Harom), 7.74
(d, 2H, JH,H = 8.5 Hz, Harom); 13C (50 MHz, CDCl3) d 14.5, 23.1, 26.5, 29.6, 29.7,
29.8, 31.5, 32.2, 32.3, 65.3, 68.2, 72.0, 76.5, 80.2, 114.2, 115.7, 127.9, 134.2, 136.2,
155.6, 161.9.
Anal. Calcd for C27H37BO5 (452.40): C, 71.68; H, 8.24. Found: C, 70.99; H, 8.16.
(1S,6R,8R)-8-(4-Methoxymethoxyphenyl)-3-(4-methoxyphenyl)-2,4,7-trioxa-3-
20
borabicyclo[4.4.0]decane (10a): yield 57%; mp 137.2°C; [a]D + 30.0 (c 0.5,
1
CHCl3); H NMR (300 MHz, CDCl3) d 1.68–1.92 (m, 2H, H-9), 2.04 (m, 1H, H-10),

700
Bertini et al.
2.38 (m, 1H, H-10), 3.46 (s, 3H, OCH3), 3.72 (ddd, 1H, J6,5a = 10.3, J6,1 = 9.2,
J6,5b = 5.1 Hz, H-6), 3.82 (s, 3H, OCH3), 3.87 (m, 1H, H-1), 3.95 (dd, 1H,
J5a,5b = 10.3, J5a,6 = 10.3 Hz, H-5a), 4.24 (dd, 1H, J5b,5a = 10.3, J5b,6 = 5.1 Hz, H-5b),
4.48 (dd, 1H, J8,9a = 10.7, J8,9eq = 1.9 Hz, H-8), 5.17 (s, 2H, OCH2O), 6.89 (d, 2H,
JH,H = 8.5 Hz, Harom), 7.04 (d, 2H, JH,H = 8.8 Hz, Harom), 7.28 (d, 2H, JH,H = 8.8 Hz,
H
arom), 7.75 (d, 2H, JH,H = 8.5 Hz, Harom); 13C (75 MHz, CDCl3) d 31.2, 32.9, 55.1,
56.0, 64.9, 71.6, 76.1, 79.8, 94.5, 113.3, 116.3, 127.3, 135.0, 135.8, 156.9, 162.0.
Anal. Calcd for C21H25BO6 (384.24): C, 65.64; H, 6.56. Found: C, 65.43;
H, 6.49.
(1S,6R,8R)-3-(4-Butyloxyphenyl)-8-(4-methoxymethoxyphenyl)-2,4,7-trioxa-3-
20
borabicyclo[4.4.0]decane (10b): yield 64%; mp 97.7°C; [a]D + 19.6 (c 0.4,
1
CHCl3); H NMR (300 MHz, CDCl3) d 0.97 (t, 3H, JH,H = 7.4 Hz, CH3), 1.47 (m,
2H, CH2), 1.70–1.90 (m, 4H, H-9, CH2), 2.03 (m, 1H, H-10), 2.38 (m, 1H, H-10), 3.46
(s, 3H, OCH3), 3.61 (ddd, 1H, J6,5a = 10.2, J6,1 = 9.2, J6,5b = 5.1 Hz, H-6), 3.84–4.00
(m, 4H, H-1, H-5a, OCH2), 4.23 (dd, 1H, J5a,5b = 10.7, J5a,6 = 5.1 Hz, H-5b), 4.48 (dd,
1H, J8,9ax = 11.2, J8,9eq = 2.0 Hz, H-8), 5.16 (s, 2H, OCH2O), 6.86 (d, 2H, JH,H = 8.6
Hz, Harom), 7.02 (d, 2H, JH,H = 8.6 Hz, Harom), 7.27 (d, 2H, JH,H = 8.6 Hz, Harom), 7.73
(d, 2H, JH,H = 8.6 Hz, Harom); 13C (75 MHz, CDCl3) d 13.9, 19.3, 31.1, 31.3, 32.9,
55.4, 64.8, 67.4, 71.5, 76.0, 79.7, 94.4, 113.7, 116.2, 127.3, 134.9, 135.7, 156.9, 161.5.
Anal. Calcd for C24H31BO6 (426.32): C, 67.62; H, 7.33. Found: C, 67.26; H, 7.23.
(1S,6R,8R)-3-(4-Hexyloxyphenyl)-8-(4-methoxymethoxyphenyl)-2,4,7-trioxa-3-
20
borabicyclo[4.4.0]decane (10c): yield 66%; mp 96.4°C; [a]D + 22.2 (c 0.5,
1
CHCl3); H NMR (300 MHz, CDCl3) d 0.90 (t, 3H, JH,H = 6.6 Hz, CH3), 1.27–1.37
(m, 4H, CH2), 1.45 (m, 2H, CH2), 1.72–1.92 (m, 4H, H-9, CH2), 2.04 (m, 1H, H-10),
2.38 (m, 1H, H-10), 3.47 (s, 3H, OCH3), 3.63 (ddd, 1H, J6,5a = 10.3, J6,1 = 9.9,
J6,5b = 5.5 Hz, H-6), 3.84–4.02 (m, 4H, H-1, H-5a, OCH2), 4.24 (dd, 1H, J5b,5a = 10.3,
J5b,6 = 5.5 Hz, H-5b), 4.50 (dd, 1H, J8,9ax = 9.9, J8,9eq = 1.8 Hz, H-8), 5.17 (s, 2H,
OCH2O), 6.86 (d, 2H, JH,H = 8.5 Hz, Harom), 7.02 (d, 2H, JH,H = 8.8 Hz, Harom), 7.29
(d, 2H, JH,H = 8.8 Hz, Harom), 7.74 (d, 2H, JH,H = 8.5 Hz, Harom); 13C (75 MHz,
CDCl3) d 13.9, 25.6, 25.7, 29.2, 31.6, 32.0, 33.1, 55.9, 64.8, 67.4, 71.5, 76.0, 79.7,
94.4, 113.7, 116.2, 127.3, 134.9, 135.7, 156.9, 161.5.
Anal. Calcd for C26H35BO6 (454.38): C, 68.73; H, 7.76. Found: C, 68.36; H, 7.77.
(1S,6R,8R)-8-(4-Methoxymethoxyphenyl)-3-(4-octyloxyphenyl)-2,4,7-trioxa-3-
20
borabicyclo[4.4.0]decane (10d): yield 62%; mp 71.7°C; [a]D + 20.2 (c 0.4,
CHCl3); 1H NMR (300 MHz, CDCl3) d 0.88 (t, 3H, J = 7.0 Hz, CH3), 1.25–1.38
(m, 8H, CH2), 1.44 (m, 2H, CH2), 1.72–1.92 (m, 4H, H-9, CH2), 2.04 (m, 1H, H-10),
2.38 (m, 1H, H-10), 3.47 (s, 3H, OCH3), 3.63 (ddd, 1H, J6,5a = 10.3, J6,1 = 9.6,
J6,5b = 5.1 Hz, H-6), 3.84–4.02 (m, 4H, H-1, H-5a, OCH2), 4.24 (dd, 1H, J5b,5a = 10.3,
J5b,6 = 5.1 Hz, H-5b), 4.48 (bd, 1H, J8,9ax = 10.1 Hz, H-8), 5.17 (s, 2H, OCH2O), 6.87
(d, 2H, JH,H = 8.5 Hz, Harom), 7.02 (d, 2H, JH,H = 8.5 Hz, Harom), 7.28 (d, 2H,
JH,H = 8.5 Hz, Harom), 7.73 (d, 2H, JH,H = 8.5 Hz, Harom); 13C (75 MHz, CDCl3) d
14.5, 23.0, 26.4, 29.6, 29.7, 29.8, 31.3, 32.2, 33.5, 55.9, 64.8, 67.4, 71.5, 76.0, 79.7,
94.4, 113.7, 116.2, 127.3, 134.9, 135.7, 156.9, 161.9.
Anal. Calcd for C28H39BO6 (482.43): C, 69.71; H, 8.15. Found: C, 69.54; H, 8.25.

Enantiopure Trioxadecalin Derived Liquid Crystals
701
(1S,6R,8R)-8-(4-Dimethylaminophenyl)-3-(4-methoxyphenyl)-2,4,7-trioxa-3-
20
borabicyclo[4.4.0]decane (11a): yield 57%; mp 188.2°C; [a]D + 25.1 (c 0.5,
1
CHCl3); H NMR (300 MHz, CDCl3) d 1.68–1.92 (m, 2H, H-9), 2.00 (m, 1H, H-10),
2.38 (m, 1H, H-10), 2.93 (s, 6H, NMe2), 3.62 (ddd, 1H, J6,5a = 10.3, J6,1 = 9.6,
J6,5b = 5.1 Hz, H-6), 3.82 (s, 3H, OCH3), 3.89 (m, 1H, H-1), 3.96 (dd, 1H,
J5a,5b = 10.3, J5a,6 = 10.3 Hz, H-5a), 4.24 (dd, 1H, J5b,5a = 10.3, J5b,6 = 5.1 Hz, H-5b),
4.45 (dd, 1H, J8,9ax = 10.7, J8,9eq = 2.2 Hz, H-8), 6.72 (d, 2H, JH,H = 8.8 Hz, Harom),
6.89 (d, 2H, JH,H = 8.5 Hz, Harom), 7.24 (d, 2H, JH,H = 8.8 Hz, Harom), 7.76 (d, 2H,
JH,H = 8.5 Hz, Harom); 13C (75 MHz, CDCl3) d 31.2, 32.9, 55.1, 55.4, 58.5, 64.9, 71.6,
76.1, 79.8, 113.3, 113.7, 127.3, 135.7, 135.8, 159.3, 161.5.
Anal. Calcd for C21H26BNO4 (367.25): C, 68.68; H, 7.14. Found: C, 68.26; H, 7.01.
(1S,6R,8R)-3-(4-Butyloxyphenyl)-8-(4-dimethylaminophenyl)-2,4,7-trioxa-3-
borabicyclo[4.4.0]decane (11b): yield 63%; mp 147.2°C; [a]D20 + 22.3 (c 0.3,
1
CHCl3); H NMR (300 MHz, CDCl3) d 0.98 (t, 3H, JH,H = 7.6 Hz, CH3), 1.50 (m, 2H,
CH2), 1.69–1.80 (m, 3H, H-9, CH2), 1.88 (m, 1H, H-9), 2.01 (m, 1H, H-10), 2.36 (m,
1H, H-10), 2.94 (s, 6H, NMe2), 3.61 (ddd, 1H, J6,5a = 10.2, J6,1 = 9.2, J6,5b = 5.1 Hz,
H-6), 3.82–4.02 (m, 4H, H-1, H-5a, OCH2), 4.23 (dd, 1H, J5b,5a = 10.2, J5b,6 = 5.1 Hz,
H-5b), 4.45 (dd, 1H, J8,9ax = 11.2, J8,9eq = 2.0 Hz, H-8), 6.74 (d, 2H, JH,H = 8.1 Hz,
H
arom), 6.88 (d, 2H, JH,H = 8.7 Hz, Harom), 7.23 (d, 2H, JH,H = 8.7 Hz, Harom), 7.74 (d,
2H, JH,H = 8.1 Hz, Harom); 13C (100 MHz, CDCl3) d 13.9, 19.2, 31.1, 31.3, 35.5, 40.8,
64.9, 67.4, 71.6, 76.0, 80.1, 113.7, 113.8, 127.3, 133.6, 135.7, 159.2, 161.5.
Anal. Calcd for C24H32BNO4 (409.34): C, 70.42; H, 7.88. Found: C, 69.99; H,
7.63.
(1S,6R,8R)-8-(4-Dimethylaminophenyl)-3-(4-hexyloxyphenyl)-2,4,7-trioxa-3-
20
borabicyclo[4.4.0]decane (11c): yield 62%; mp 141.5°C; [a]D + 24.2 (c 0.4,
1
CHCl3); H NMR (300 MHz, CDCl3) d 0.90 (t, 3H, JH,H = 7.4 Hz, CH3), 1.29–1.37
(m, 4H, CH2), 1.46 (m, 2H, CH2), 1.70–1.92 (m, 4H, H-9, CH2), 2.02 (m, 1H, H-10),
2.37 (m, 1H, H-10), 2.93 (s, 6H, NMe2), 3.62 (ddd, 1H, J6,5a = 10.3, J6,1 = 9.6,
J6,5b = 5.1 Hz, H-6), 3.82–4.02 (m, 4H, H-1, H-5a, OCH2), 4.23 (dd, 1H, J5b,5a = 10.3,
J5b,6 = 5.1 Hz, H-5b), 4.45 (dd, 1H, J8,9ax = 11.0, J8,9eq = 1.8 Hz, H-8), 6.72 (d, 2H,
JH,H = 8.5 Hz, Harom), 6.88 (d, 2H, JH,H = 8.5 Hz, Harom), 7.23 (d, 2H, JH,H = 8.5 Hz,
H
25.8, 29.2, 31.6, 32.0, 33.1, 64.9, 67.8, 71.6, 76.0, 80.0, 113.7, 127.2, 128.5, 135.7,
159.3, 161.5.
arom), 7.74 (d, 2H, JH,H = 8.5 Hz, Harom); 13C (75 MHz, CDCl3) d 14.1, 22.6,
Anal. Calcd for C26H36BNO4 (437.39): C, 71.40; H, 8.30. Found: C, 71.14; H, 8.48.
(1S,6R,8R)-8-(4-Dimethylaminophenyl)-3-(4-octyloxyphenyl)-2,4,7-trioxa-3-
borabicyclo[4.4.0]decane (11d): yield 58%; mp 110.7°C; [a]D20 + 22.3 (c 0.3,
1
CHCl3); H NMR (300 MHz, CDCl3) d 0.90 (t, 3H, JH,H = 7.0 Hz, CH3), 1.20–1.38
(m, 8H, CH2), 1.45 (m, 2H, CH2), 1.72–1.92 (m, 4H, H-9, CH2), 2.01 (m, 1H, H-10),
2.38 (m, 1H, H-10), 2.94 (s, 6H, NMe2), 3.61 (ddd, 1H, J6,5a = 10.3, J6,1 = 9.9,
J6,5b = 5.1 Hz, H-6), 3.82–4.02 (m, 4H, H-1, H-5a, OCH2), 4.23 (dd, 1H, J5b,5a = 10.3,
J5b,6 = 5.1 Hz, H-5b), 4.45 (dd, 1H, J8,9ax = 11.0, J8,9eq = 2.9 Hz, H-8), 6.71 (d, 2H,
JH,H = 8.8 Hz, Harom), 6.88 (d, 2H, JH,H = 8.8 Hz, Harom), 7.23 (d, 2H, JH,H = 8.8 Hz,

702
Bertini et al.
Harom), 7.74 (d, 2H, JH,H = 8.8 Hz, Harom); 13C (75 MHz, CDCl3) d 14.1, 22.7, 26.0,
29.3, 29.4, 31.2, 31.8, 32.5, 64.9, 67.8, 71.6, 76.0, 80.0, 113.7, 127.2, 128.5, 135.7,
159.3, 161.5.
Anal. Calcd for C28H40BNO4 (465.44): C, 72.26; H, 8.66. Found: C, 71.68; H,
8.37.
ACKNOWLEDGMENTS
B. B. thanks the French Ministry of Education for a fellowship. Financial support
by DAAD/Procope Programme is gratefully acknowledged.
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Received February 7, 2003
Accepted August 8, 2003