1,2-bridged calix[4]arene monocrowns and biscrowns in the 1,2-alternate conformation

Article abstract of DOI:10.1021/jo9810516

The condensation of 1,2-di[(2-pyridylmethyl)oxy]calix[4]arenes 1 (R = (t)Bu, H) with glycol ditosylates 2a-e in anhydrous toluene in the presence of (t)BuOK has led to a mixture of 1,2-alternate and cone 1,2-calix[4]arene crown conformers 3 and 4, respectively. Similarly, the reaction of 1,2- bridged calix[4]arene crown-4 5 with tri- to pentaethylene glycol ditosylates 2a-c has produced 1,2-alternate and cone calix[4]arene biscrown conformers 6 and 7, respectively. The distribution of conformers depends on the para- substituent at the upper rim and the length and bulkiness of the ditosylates. The best yields of the 1,2-alternate conformer (up to 51%) are observed in the absence of (t)Bu groups and with the longer polyether chain. The conformational features of 3 and 6 have been deduced by NMR spectroscopy and by X-ray crystallography. X-ray analysis of 25,26-27,28-biscrown-4- calix[4]arene (6a) shows that there are two independent molecules in the asymmetric unit, both in the 1,2-alternate conformation.

Full text of DOI:10.1021/jo9810516

J . Org. Chem. 1998, 63, 9703-9710
9703
1,2-Br id ged Ca lix[4]a r en e Mon ocr ow n s a n d Biscr ow n s in th e
1,2-Alter n a te Con for m a tion †
George Ferguson,‡ Alan J . Lough,§ Anna Notti, Sebastiano Pappalardo,*,|
Melchiorre F. Parisi, and Ada Petringa
Department of Chemistry and Biochemistry, University of Guelph, Guelph, Ontario, Canada N1G 2W1,
Department of Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 3H6, Dipartimento di
Chimica Organica e Biologica, Universita` di Messina, Salita Sperone 31, I-98166 Vill. S. Agata,
Messina, Italy, and Dipartimento di Scienze Chimiche, Universita` di Catania, Viale A. Doria 6,
I-95125 Catania, Italy
Received J une 2, 1998
The condensation of 1,2-di[(2-pyridylmethyl)oxy]calix[4]arenes 1 (R ) tBu, H) with glycol ditosylates
t
2a -e in anhydrous toluene in the presence of BuOK has led to a mixture of 1,2-alternate and
cone 1,2-calix[4]arene crown conformers 3 and 4, respectively. Similarly, the reaction of 1,2-bridged
calix[4]arene crown-4 5 with tri- to pentaethylene glycol ditosylates 2a -c has produced 1,2-alternate
and cone calix[4]arene biscrown conformers 6 and 7, respectively. The distribution of conformers
depends on the para-substituent at the upper rim and the length and bulkiness of the ditosylates.
The best yields of the 1,2-alternate conformer (up to 51%) are observed in the absence of tBu groups
and with the longer polyether chain. The conformational features of 3 and 6 have been deduced by
NMR spectroscopy and by X-ray crystallography. X-ray analysis of 25,26-27,28-biscrown-4-calix-
[4]arene (6a ) shows that there are two independent molecules in the asymmetric unit, both in the
1,2-alternate conformation.
In tr od u ction
by the inability to get in situ the ideal anti-distal
dialkylated precursors,2b the isomeric syn-proximal5 or
syn-distal6 intermediates being generally observed, ac-
cording to the nature and strength of the base used.
Calix[4]arenes are commonly used as three-dimen-
sional building blocks for the construction of more
elaborate host molecules with desired properties.1 Owing
to their nonplanar structure, calix[4]arenes can be locked
in one of the four extreme conformations, i.e., cone,
partial cone, 1,3-alternate, and 1,2-alternate. However,
despite the undeniable advances in the stereocontrolled
functionalization of calix[4]arenes, direct methods for the
attainment of calix[4]arenes in the 1,2-alternate confor-
mation are still lacking.2 Except for some specific cases,3,4
the 1,2-alternate conformation appears to be precluded
In the frame of a general project aimed at the com-
parative evaluation of the complexation properties of
regioisomers and conformational isomers of di[(2-pyridyl-
methyl)oxy]-p-tert-butylcalix[4]arene crown ethers,7 we
have tackled the synthesis of 1,2-alternate calix[4]arene
crowns. This conformation provides a potentially useful
binding geometry, in which the soft character of two
adjacent aromatic nuclei could act cooperatively with the
facing crown moiety in metal ion recognition.
† In memory of the late Professor Pasquale Notti.
Earlier we have shown that readily available syn-
proximal di[(2-pyridylmethyl)oxy]calixarenes 1 (R ) tBu,
H) represent useful starting materials for the attainment
of calix[4]arene crown ethers in this particular conforma-
tion.8 In this paper, we report full details of the reaction
of 1 with ditosylates 2 for the synthesis of the relevant
1,2-calix[4]arene crown ethers in the 1,2-alternate con-
formation. In the course of this work, Arduini et al. have
reported the synthesis of 1,2-bridged p-tert-butylcalix[4]-
arene biscrowns in the 1,2-alternate conformation, em-
phasizing the necessity of tBu substituents in the stereo-
control of the reaction.9 Since these observations were
not in agreement with our previous findings,8 we were
‡ University of Guelph.
§ University of Toronto.
Universita` di Messina.
| Universita` di Catania.
(1) For full reviews on calixarene chemistry, cf.: (a) Gutsche, C. D.
Calixarenes. In Monographs in Supramolecular Chemistry; Stoddart,
J . F., Ed.; Royal Society of Chemistry: Cambridge, U.K., 1989. (b)
Calixarenes, A Versatile Class of Macrocyclic Compounds; Vicens, J .,
Bo¨hmer, V., Eds.; Kluwer: Dordrecht, The Netherlands, 1991. (c)
Bo¨hmer, V. Angew. Chem., Int. Ed. Engl. 1995, 34, 713. (d) Ikeda, A.;
Shinkai, S. Chem. Rev. 1997, 97, 1713.
(2) For the stepwise synthesis of 1,2-alternate calix[4]arenes by
protection-deprotection methods, see: (a) Groenen, L. C.; van Loon,
J .-D.; Verboom, W.; Harkema, S.; Casnati, A.; Ungaro, R.; Pochini, A.;
Ugozzoli, F.; Reinhoudt, D. N. J . Am. Chem. Soc. 1991, 113, 2385. (b)
Iwamoto, K.; Araki, K.; Shinkai, S. J . Chem. Soc., Perkin Trans. 1 1991,
1611. (c) Iwamoto, K.; Araki, K.; Shinkai, S. J . Org. Chem. 1991, 56,
4955. (d) Iwamoto, K.; Shinkai, S. J . Org. Chem. 1992, 57, 7066.
(3) Gibbs, C. G.; Gutsche, C. D. J . Am. Chem. Soc. 1993, 115, 5338.
Gibbs, C. G.; Sujieeth, P. K.; Rogers, J . S.; Stanley, G. G.; Krawiec,
M.; Watson, W. H.; Gutsche, C. D. J . Org. Chem. 1995, 60, 8394.
(4) Minute amounts of 1,2-alternate calix[4]arenes have been spo-
radically observed in the exhaustive alkylation or acylation of the
parent calix[4]arenes: (a) J aime, C.; de Mendoza, J .; Prados, P.; Nieto,
P. M.; Sa´nchez, C. J . Org. Chem. 1991, 56, 3372. (b) Iwamoto, K.; Araki,
K.; Shinkai, S. J . Org. Chem. 1991, 56, 4955. (c) Pappalardo, S.;
Ferguson, G.; Neri, P.; Rocco, C. J . Org. Chem. 1995, 60, 4576. (d)
Akabori, S.; Sannohe, H.; Habata, Y.; Mukoyama, Y.; Ishii, T. Chem.
Commun. 1996, 1467. (e) Neri, P.; Bottino, A.; Geraci, C.; Piattelli, M.
Tetrahedron: Asymmetry 1996, 7, 17.
(5) Bottino, F.; Giunta, L.; Pappalardo, S. J . Org. Chem. 1989, 54,
5407. Groenen, L. C.; Ruel, B. H. M.; Casnati, A.; Timmerman, P.;
Verboom, W.; Harkema, S.; Pochini, A.; Ungaro, R. Tetrahedron Lett.
1991, 32, 2675.
(6) Collins, E. M.; McKervey, M. A.; Harris, S. J . J . Chem. Soc.,
Perkin Trans. 1 1989, 372. van Loon, J .-D.; Arduini, A.; Verboom, W.;
Ungaro, R.; van Hummel, G. J .; Harkema, S.; Reinhoudt, D. N.
Tetrahedron Lett. 1989, 30, 2681.
(7) Arnaud-Neu, F.; Ferguson, G.; Fuangswasdi, S.; Notti, A.;
Pappalardo, S.; Parisi, M. F.; Petringa, A. J . Org. Chem. 1998, 63, 7770.
(8) For a preliminary communication, see: Pappalardo, S.; Petringa,
A.; Parisi, M. F.; Ferguson, G. Tetrahedron Lett. 1996, 37, 3907.
10.1021/jo9810516 CCC: $15.00 © 1998 American Chemical Society
Published on Web 12/02/1998

9704 J . Org. Chem., Vol. 63, No. 26, 1998
Ferguson et al.
Sch em e 1
Sch em e 3
Sch em e 2
prompted to extend our studies to the synthesis of 1,2-
t
alternate calix[4]arene biscrowns devoid of Bu groups
at the upper rim.
difference between these conformers,11 which may even-
tually lead to better yields of the 1,2-alternate derivatives
by reaction with bifunctional electrophiles, in the light
of the plausible reaction pathways depicted in Scheme
3. Upon cyclization with glycol ditosylates, [C-1]2- can
only afford, via intermediate A, the cone conformers 4
(path a). [P C-1]2-, on the other hand, can yield both 4
and the 1,2-alternate conformers 3 (paths b and c,
respectively), after inversion of the residual phenoxide
group on the initial tosylated intermediate (A1 f A or
B1 f B, Scheme 3).
Resu lts a n d Discu ssion
P r elim in a r y Rem a r k s. Previous studies have estab-
lished that the exhaustive alkylation of calix[4]arenes
with weak bases, such as metal carbonates, proceeds
through a sequence of mono-deprotonation/alkylation
steps.10 MM2 calculations have shown that the mono-
anion generated from 1,2-alkylated calix[4]arenes 1 can
assume both cone [C-1]- and 1,2-alternate [ALT-1]-
conformations, which are preferred over other conforma-
tions by favorable hydrogen bonding of the phenolate
moiety with the adjacent OH group (Scheme 1).11 Al-
though the 1,2-alternate conformer is only 1-2 kcal mol-1
less stable than the cone, initial reaction of 5,11,17,23-
tetrakis(1,1-dimethylethyl)-25,26-bis[(2-pyridylmethyl)-
oxy]-27,28-dihydroxycalix[4]arene (1a ) with triethylene
glycol ditosylate (2a , 1.1 equiv) and K2CO3 (excess) in dry
DMF at 70 °C has produced only a trace amount of the
1,2-alternate p-tert-butylcalix[4]arene crown-4 3a , the
main compound being the cone conformer 4a (Scheme
2).
Whereas the use of hard bases (NaH) in DMF did not
succeed for the production of 1,2-alternate calix[4]arene
crowns, satisfactory results were obtained with softer
bases (tBuOK) and low polarity solvents such as toluene.
Syn th esis of 1,2-Alter n ate 1,2-Di[(2-pyr idylm eth yl)-
oxy]ca lix[4]a r en e Cr ow n Eth er s. When calixarenes
1 were subjected to ditosylates 2a -e (1.1 equiv) in
t
toluene at 70 °C in the presence of BuOK (2.2 equiv), a
mixture of 1,2-alternate and cone calix[4]arene crown
ethers 3 and 4, respectively, was formed in most cases
(Table 1). Due to the different polarity of the two
On the other hand, deprotonation of 1 with 2 equiv of
a stronger base affords two dianionic conformers, cone
[C-1]2- and partial cone [P C-1]2-, in equilibrium. In this
case, MM2 calculations have shown a negligible energy
(9) Arduini, A.; Domiano, L.; Pochini, A.; Secchi, A.; Ungaro, R.;
Ugozzoli, F.; Struck, O.; Verboom, W.; Reinhoudt, D. N. Tetrahedron
1997, 53, 3767.
(10) van Loon, J .-D.; Verboom, W.; Reinhoudt, D. N. Org. Prep. Proc.
Intl. 1992, 24, 437.
(11) Pappalardo, S.; Giunta, L.; Foti, M.; Ferguson, G.; Gallagher,
J . F.; Kaitner, B. J . Org. Chem. 1992, 57, 2611.

1,2-Bridged Calix[4]arene Mono- and Biscrowns
J . Org. Chem., Vol. 63, No. 26, 1998 9705
Ta ble 1. Isola ted Yield s of 1,2-Alter n a te a n d Con e
Mon ocr ow n Con for m er s in th e Rea ction of 1 w ith 2 a n d
tBu OK in Tolu en e a t 70 °C
Ta ble 2. Isola ted Yield s of 1,2-Alter n a te a n d Con e
Biscr ow n Con for m er s in th e Rea ction of 5 w ith 2a -c a n d
tBu OK in Tolu en e a t 70 °C
shorter glycolic chain, due to severe steric interactions
t
with the upper rim Bu groups. In agreement with this
interpretation, the reaction of 1b (R ) H) with 2d
restored the usual mixture of conformers (Table 1, entry
8).
These findings clearly indicate that both the length and
steric encumbrance of the ditosylate, as well as the
bulkiness of the para-substituent at the upper rim, play
a role in the conformational outcome of this reaction. The
distribution of conformers is determined by the ratio of
the relative rates of the first alkylation step of the
phenolate groups in different chemical environments (syn
or anti to picolyl groups). The stabilization of the relevant
transition states likely results from a balance between
steric interactions and a possible template effect of the
potassium ion.
Syn th esis of 1,2-Br id ged Ca lix[4]a r en e Biscr ow n s
in th e 1,2-Alter n a te Con for m a tion . In all cases dis-
cussed above, comparatively higher yields of the 1,2-
alternate conformers are always observed in the absence
conformers, their separation was easily achieved by
column chromatography, the 1,2-alternate conformers 3
generally being less polar than cone 4. In the case of
crown ethers that incorporate the binaphthyl moiety and
t
of Bu groups at the upper rim of the starting 1,2-di-O-
alkylated calix[4]arene (Table 1). This contradicts re-
t
t
are devoid of Bu substituents at the upper rim of the
cently published findings which suggest that the Bu
calixarene skeleton, the chromatographic behavior is
reversed, the cone conformers 4h and 4j representing the
fastest moving components.
substituents at the upper rim of the parent calix[4]arene
are necessary to ensure stereochemical control in the
direct synthesis of the structurally related 1,2-bridged
calix[4]arene biscrowns in the 1,2-alternate conforma-
tion.9 More specifically, the 1,2-bridged p-H-calix[4]arene
biscrown-4 in the cone conformation (compound 7a ) was
reported to be the only product isolated, whatever the
starting material (p-H-calix[4]arene or 1,2-bridged p-H-
calix[4]arene crown-4 5) and the conditions applied (2a ,
The yield of isolated product is shown in Table 1. In
the reactions of 1 with ditosylates 2a ,b (Table 1, entries
1-4), the 1,2-alternate/cone ratio is ca. 12:1 with the
shorter polyether chain (crown-4), and roughly 1:1 with
the chain of intermediate length (crown-5), irrespective
of the para-substituent. Conversely, with the longer
ditosylate 2c (Table 1, entries 5 and 6) the para-
substituent has an effect, the 1,2-alternate crown-6
conformer clearly prevailing over cone (ratio 4:1) in the
t
t
NaH in DMF, BuOK or BuOCs in toluene).9
To throw light on this controversial point, we have
t
revisited the reaction of 5 with 2a and BuOK in toluene
t
absence of Bu groups at the upper rim. Interestingly,
and extended it to the longer ditosylates 2b,c (see Table
2). In our hands, the reaction has invariably produced
the expected mixtures of 1,2-alternate and cone biscrown
derivatives 6 and 7, respectively, confirming our earlier
observations8 and the general applicability of the present
procedure.
The yield of isolated product in the reactions of 5 with
2a -c is shown in Table 2. The yield of the 1,2-alternate
conformers 6 is in the range 25-45% and increases with
increasing length of the polyether chain. The relatively
t
when 1a (R ) Bu) was treated with the binaphthyl-
containing ditosylates 2d ,e (Table 1, entries 7 and 9) the
yield of 1,2-alternate crown-6 conformer 3i dropped to
6%, while the smaller crown-4 derivative 3g was not even
detected in the reaction mixture. Inspection of molecular
models suggests that the approach of the bulky binaph-
thyl-containing ditosylates to the inverted phenolate
group in [P C-1]2-, leading to intermediate B1 (Scheme
3), is difficult with 2e and prevented with 2d , having a

9706 J . Org. Chem., Vol. 63, No. 26, 1998
Ferguson et al.
high yield of mixed crown-4-crown-5 derivative 7b (55%)
could be explained by a very favorable template effect of
the potassium ion, in the light of the known ability of
1,2-bridged calix[4]arene biscrowns (cone conformers) to
strongly bind alkali-metal ions.12,13
NMR Ch a r a cter iza tion Stu d ies. Structures and
conformations of all new compounds were established by
FAB (+) MS, 1H and 13C NMR spectroscopies, and single-
crystal X-ray analyses (for 3c and 6a ). The NMR probes
are especially useful for establishing calix[4]arene con-
formations, taking advantage of the well-documented
1
patterns of the H NMR resonances (particularly those
arising from ArCH2Ar1a and OCH2Py groups14) and the
position of the 13C NMR resonances associated with the
same groups.4a
F igu r e 1. Views of the two molecules of 6a at 123 K with
our numbering scheme. For clarity, H atoms are omitted and
displacement ellipsoids are drawn at the 10% probability level.
The 1H NMR spectra of 1,2-alternate monocrowns 3
and mixed biscrowns 6b,c display two AX systems (J )
12.4 ( 0.3 Hz) and an AB quartet (J ) 17.1 ( 0.5 Hz) in
the ratio 1:1:2 for the ArCH2Ar groups (one AX system
and one singlet in the ratio 1:1 in the case of the highly
symmetrical biscrown 6a ). Compounds 3 show an ad-
ditional AB system for the diastereotopic OCH2Py pro-
tons (two AB systems for binaphthyl-containing deriva-
tives 3h -j, owing to the axial chirality of this subunit).
The 13C NMR spectra of 1,2-alternate structures exhibit
two resonances in the range 28-30 ppm (one resonance
for 6a ) and one resonance of double intensity at 37-39
ppm (two distinct resonances in the case of racemic 3h -
j) for the bridging methylene carbons, and a very
diagnostic14 resonance at 74.5 ( 0.1 ppm for OCH2Py
groups (two distinct resonances for 3h -j). The uniformity
of the spectra of 3a -f clearly indicates that these
compounds in solution adopt a similar conformation.
1,2-Bridged monocrown and mixed biscrown cone
conformers 4a -f and 7b,c show the expected proton and
carbon NMR spectral patterns for a mixed bis-syn-
proximal functionalization at the lower rim of calix[4]-
arenes [in particular, a set of three AX systems (J ) 12.9
( 0.6 Hz) for ArCH2Ar in the ratio 1:2:1 and three
resonances for the pertinent carbons at δ 29-31 ppm].11,15
Obviously, binaphthyl-containing derivatives 4g-j dis-
play four AX systems (ratio 1:1:1:1) for ArCH2Ar protons
and four resonances for the relevant carbons.
one of the two picolyl groups is leaning toward the
hemicavity. In the attempt to freeze in solution this
transient chiral conformation, a VT-NMR study on 3c
in CD2Cl2 was conducted. Unfortunately, the motion of
the picolyl groups is still fast even at -90 °C. It is
interesting to note, however, that sterically congested
binaphthyl derivatives 3h ,i assume in solution a con-
formation in which only one of the two picolyl groups
resides in the hemicavity, as suggested by the presence
of a single high-field resonance for the H3 (5.62 ppm in
3h and 5.93 ppm in 3i) integrating for one proton. In
contrast, the more flexible 3j displays two distinct sig-
nals for the relevant pyridyl protons at 6.11 and 6.18
ppm.
X-r a y An a lysis of 6a . X-ray analysis16
of 6a shows
that there are two independent molecules in the crystal
asymmetric unit and that both molecules have very
similar conformations. The molecules are inherently
chiral, and the asymmetric unit of the centrosymmetric
crystal system was chosen so that it contained one
molecule of each chirality. Views of the two molecules
are in Figure 1. The torsion angles φ and ø describing
the conformations19 (Table 3) correspond with the sym-
bolic representation +-, ++, -+, --, and are entirely
in accord with the 1,2-alternate conformation. An exactly
comparable conformation was recently noted for the
A comparison of the 1H NMR spectra of 3 and 4 reveals
strong upfield shifts for a pair of symmetrical oxyethylene
protons and for the pyridyl protons of the 1,2-alternate
structures 3, which are respectively exposed to the
diamagnetic shielding effect of two pairs of aryl rings (one
above and one below the mean methylene-containing
plane). The conspicuous upfield shift experienced by H3
(∆δ ca. 1.7 ppm) and to a lesser extent by H4 (∆δ ca. 0.8
ppm) picolyl protons further suggests that (a) the hetero-
aromatic pendant groups alternate in filling the pocket
created by the two facing aryl rings and (b) the ring
nitrogen is exo to the calix cup and anti oriented with
respect to the phenolic oxygen.
t
corresponding Bu derivative.9 The conformation of the
6a molecules is also defined by the interplanar angles
which the aromatic rings make with the best plane
through the four methylene carbons which link them;
these data are shown in Table 4.
(16) Crystals of 6a , C40H44O8, are orthorhombic, space group Pbca,
with cell data (at 123 K): a ) 16.3267(4), b ) 19.8109(4), and c )
41.4114(10) Å, V ) 13394.4(5) Å3, Z ) 16, Dx ) 1.295 g cm-3, F(000)
) 5568. A crystal of dimensions 0.25 × 0.20 × 0.08 mm was used for
the data collection with a Nonius KappaCCD system at 123 K and
using graphite-monochromated Mo KR radiation to a maximum θ value
of 24.71°. In all, some 54999 reflections were measured; these reduced
to 11334 unique reflections of which 6196 had I > 2σ (I). The structure
was solved by direct methods using SHELXLS-9717 and refined using
all available data with SHELXL-97.18 Hydrogen atoms were visible in
difference maps and allowed for as riding atoms. All non-H atoms were
allowed anisotropic displacement parameters. Final R-factors are
0.0540 for R(obs) and 0.1349 for Rw (all F2 data). Final difference maps
were featureless. Full details of the crystallographic results have been
deposited in CIF format and are also available from the authors.
(17) Sheldrick, G. M. SHELXS97. Program for the solution of crystal
structures; University of Go¨ttingen, Germany, 1997.
The 1,2-alternate conformation of 3c was further
proven by single-crystal X-ray analysis.8 In the crystal,
(12) Arduini, A.; Casnati, A.; Dodi, L.; Pochini, A.; Ungaro, R. J .
Chem. Soc., Chem. Commun. 1990, 1597. Arduini, A.; Casnati, A.;
Fabbi, M.; Minari, P.; Pochini, A.; Sicuri, A. R.; Ungaro, R. Supramol.
Chem. 1993, 1, 235.
(13) Asfari, Z.; Astier, J .-P.; Bressot, C.; Estienne, J .; Pepe, G.;
Vicens, J . J . Inclusion Phenom. 1994, 19, 291.
(14) Bottino, F.; Pappalardo, S. J . Inclusion Phenom. 1994, 19, 85.
(15) Brunink, J . A. J .; Verboom, W.; Engbersen, J . F. J .; Harkema,
S.; Reinhoudt, D. N. Recl. Trav. Chim. Pays-Bas 1992, 111, 511.
(18) Sheldrick, G. M. SHELXL97. Program for the refinement of
crystal structures; University of Go¨ttingen, Germany, 1997.
(19) Ugozzoli, F.; Andreetti, G. D. J . Inclusion Phenom. 1992, 13,
337.

1,2-Bridged Calix[4]arene Mono- and Biscrowns
J . Org. Chem., Vol. 63, No. 26, 1998 9707
Ta ble 3. Tor sion An gles O a n d ø (d eg) for th e Tw o
disappearance of 1 (TLC analysis). After evaporation of the
solvent, the residue was partitioned between water and
CH2Cl2. The organic layer was dried over MgSO4 and concen-
trated. The crude product was separated into the pure
conformers 3 and 4 by column chromatography (SiO2, a
gradient of AcOEt in cyclohexane or CH2Cl2 as an eluent),
followed by recrystallization from an appropriate solvent
system. Further details are given for the individual com-
pounds.
Molecu les of 6a
φ
ø
molecule 1
C16-C17-C22-C23
C46-C47-C12-C13
C36-C37-C42-C43
58.4(3) C15-C16-C17-C22
149.4(3) C45-C46-C47-C12
-95.5(3) C35-C36-C37-C42
-95.5(3)
148.0(3)
61.0(3)
C26-C27-C32-C33 -119.9(3) C25-C26-C27-C32 -118.6(3)
molecule 2
5,11,17,23-T e t r a k is (1,1-d im e t h y le t h y l)-25,26-b is -
[(2-p yr id ylm eth yl)oxy]-27,28-cr ow n -4-ca lix[4]a r en e, 1,2-
Alter n a te Con for m er (3a ): 37% yield, mp 259-262 °C
(MeOH-CH2Cl2); 1H NMR δ 1.09, 1.39 (s, 18 H each), 2.61
(ddd, J ) 10.2, 5.9, 4.4 Hz, 2 H), 3.21, 3.23 (d, J ) 12.3 Hz, 1
H each), 3.26-3.69 (m, 10 H), 3.81 and 3.87 (ABq, J ) 17.4
Hz, 4 H), 4.17, 4.40 (d, J ) 12.3 Hz, 1 H each), 4.57 and 4.65
(ABq, J ) 14.2 Hz, 4 H), 6.26 (dt, J ) 7.6, 0.9 Hz, 2 H), 6.71
(td, J ) 7.6, 1.8 Hz, 2 H), 6.75 and 7.21 (AX, J ) 2.5 Hz, 4 H),
6.89 (ddd, J ) 7.6, 4.8, 1.2 Hz, 2 H), 7.08 and 7.42 (AX, J )
2.5 Hz, 4 H), 8.32 (ddd, J ) 4.8, 1.8, 0.9 Hz, 2 H); 13C NMR δ
28.5, 29.7, 38.6 (×2) (t, ArCH2Ar), 31.5, 31.8 (q, C(CH3)3), 33.9,
34.1 (s, C(CH3)3), 67.3, 69.3, 70.7 (t, OCH2CH2O), 74.5 (t, OCH2-
Py), 121.0, 121.2 (d, 3,5-Py), 125.1, 125.7 (×2), 125.9 (d, Ar),
132.49, 132.53, 133.8, 134.5 (s, bridgehead-C), 136.4 (d, 4-Py),
C56-C57-C62-C63
-61.8(3) C55-C56-C57-C62
91.2(3)
C86-C87-C52-C53 -144.5(3) C85-C86-C87-C52 -146.5(3)
C76-C77-C82-C83
C66-C67-C72-C73
87.7(3) C75-C76-C77-C82
131.1(3) C65-C66-C67-C72
-67.4(3)
119.7(3)
Ta ble 4. In ter p la n a r An gles for 6a Wh ich th e Ar om a tic
Rin gs Ma k e w ith th e P la n e of th e Meth ylen e C Atom s
Lin k in g Th em
ring atoms
angle (deg)
molecule 1
molecule 2
C11-C16
C21-C26
C31-C36
C41-C46
C51-C56
C61-C66
C71-C76
C81-C86
135.05(5)
96.71(4)
98.19(5)
134.46(5)
130.74(5)
99.98(4)
106.58(5)
130.83(5)
2
144.6, 145.2 (s, Csp -C(CH3)3), 147.9 (d, 6-Py), 153.3, 153.8 (s,
+
2
Csp -O), 158.2 (s, 2-Py); MS, m/z 945 (MH ). Anal. Calcd for
C
62H76N2O6: C, 78.78; H, 8.10; N, 2.96. Found: C, 78.57; H,
8.18; N, 2.84.
Con clu sion s
5,11,17,23-Te t r a k is(1,1-d im e t h yle t h yl)-25,26-b is[(2-
p yr id ylm eth yl)oxy]-27,28-cr ow n -4-ca lix[4]a r en e, Con e
Con for m er (4a ): 3% yield; mp 190-191 °C; H NMR δ 1.08,
We have developed a general procedure for the prepa-
ration of 1,2-bridged calix[4]arene monocrowns and bis-
crowns in the 1,2-alternate conformation and discussed
the various factors affecting the conformational outcome
in the reaction of 1,2-functionalized calix[4]arenes with
1
1.09 (s, 18 H each), 3.07, 3.10 (d, J ) 12.5 Hz, ratio 1:3, 4 H),
3.60-3.67 (m, 2 H), 3.73-3.85 (m, 6 H), 4.07-4.24 (m, 4 H),
4.33, 4.41, 4.77 (d, J ) 12.5 Hz, ratio 2:1:1, 4 H), 5.02 and
5.12 (ABq, J ) 12.7 Hz, 4 H), 6.79 and 6.81 (ABq, J ) 2.6 Hz,
4 H), 6.88 (s, 4 H), 7.18 (ddd, J ) 7.5, 4.9, 1.2 Hz, 2 H), 7.60
(td, J ) 7.5, 1.8 Hz, 2 H), 7.78 (dt, J ) 7.5, 0.9 Hz, 2 H), 8.55
(ddd, J ) 4.9, 1.8, 0.9 Hz, 2 H); 13C NMR δ 30.1, 30.6, 31.1
(×2) (t, ArCH2Ar), 31.4 (q, C(CH3)3), 33.82, 33.85 (s, C(CH3)3),
70.3, 70.5, 73.2 (t, OCH2CH2O), 78.1 (t, OCH2Py), 122.3, 123.3
(d, 3,5-Py), 124.9, 125.1, 125.2, 125.4 (d, Ar), 133.3, 133.5,
133.6, 134.4 (s, bridgehead-C), 136.5 (d, 4-Py), 144.69, 144.74
t
glycol ditosylates and BuOK in toluene. This synthetic
strategy is currently being employed for the design of new
enlarged hydrophobic cavities, based on 1,2-alternate
calix[4]arene substructures, potentially useful for the
selective inclusion of organic guests.
2
2
(s, Csp -C(CH3)3), 148.7 (d, 6-Py), 152.8, 152.9 (s, Csp -O), 158.3
(s, 2-Py); MS, m/z 945 (MH+). Anal. Calcd for C62H76N2O6: C,
78.78; H, 8.10; N, 2.96. Found: C, 78.95; H, 8.27; N. 2.88.
Cone 4a was prepared more conveniently (55% yield) by
reacting 1a with 2a (1.1 equiv) and K2CO3 (10 equiv) in dry
DMF at 70 °C for 36 h.
Exp er im en ta l Section
Gen er a l. All chemicals were reagent grade and were used
without further purification. Anhydrous toluene was obtained
commercially. Melting points were determined on a Kofler or
Electrothermal melting point apparatus and are uncorrected.
1H and 13C NMR spectra were recorded in CDCl3 at 300 and
75 MHz, respectively, with TMS as the internal standard. The
multiplicity of the 13C signals was determined with the APT
technique. Where present, peak assignments followed from
COSY and HETCOR experiments. For FAB (+) mass spectra,
3-nitrobenzyl alcohol was used as the matrix. 1,2-Di[(2-
pyridylmethyl)oxy]calix[4]arenes 1a ,b ,11 ditosylates 2a -c,20
(()-2d (mp 129-130 °C from cyclohexane-CH2Cl2 (lit.,21
viscous oil)), (()-2e,22 and 1,2-bridged calix[4]arene crown-4
523 were prepared according to reported procedures or slight
modifications thereof. All reactions were carried out under
nitrogen atmosphere.
R ea ct ion of 1 w it h Glycol Dit osyla t es 2. Gen er a l
P r oced u r e. A stirred mixture of 1 (0.5 mmol) and tBuOK (0.12
g, 1.1 mmol) in dry toluene (50 mL) was heated at 70 °C for 1
h. Then a solution of the appropriate ditosylate (0.55 mmol)
in dry toluene (30 mL) was added dropwise over 3 h. The
stirred mixture was kept at 70 °C for a further 24-36 h.
Progress of the reaction could be monitored by following the
25,26-Bis[(2-p yr id ylm eth yl)oxy]-27,28-cr ow n -4-ca lix[4]-
a r en e, 1,2-Alter n a te Con for m er (3b): 40% yield, mp 230-
233 °C (hexane-CH2Cl2); H NMR δ 2.60 (ddd, J ) 10.3, 6.0,
1
4.3 Hz, 2 H), 3.23 (m, 2 H), 3.24 and 4.37 (AX, J ) 12.7 Hz, 2
H), 3.31 and 4.28 (AX, J ) 12.5 Hz, 2 H), 3.41-3.76 (m, 8 H),
3.81 and 3.87 (ABq, J ) 17.4 Hz, 4 H), 4.61 and 4.66 (ABq, J
) 13.8 Hz, 4 H), 6.10 (ddd, J ) 7.5, 1.4, 0.9 Hz, 2 H), 6.60-
6.72 (m, 4 H), 6.88 (td, J ) 7.5, 1.9 Hz, 2 H), 6.94 (ddd, J )
7.5, 4.7, 1.4 Hz, 2 H), 7.04 (t, J ) 7.5 Hz, 2 H), 7.15 (dd, J )
7.5, 1.7 Hz, 2 H), 7.20 (dd, J ) 6.3, 3.0 Hz, 2 H), 7.38 (dd, J )
7.5, 1.7 Hz, 2 H), 8.33 (ddd, J ) 4.7, 1.9, 0.9 Hz, 2 H); 13C
NMR δ 28.0, 28.8, 37.8 (×2) (t, ArCH2Ar), 68.0, 69.9, 70.7 (t,
OCH2CH2O), 74.5 (t, OCH2Py), 121.0, 121.4 (d, 3,5-Py), 122.6,
123.1, 128.5, 129.3 (×2), 129.6 (d, Ar), 133.29, 133.32, 134.5,
135.3 (s, bridgehead-C), 136.0 (d, 4-Py), 147.9 (d, 6-Py), 155.2,
+
2
156.0 (s, Csp -O), 157.6 (s, 2-Py); MS, m/z 721 (MH ). Anal.
Calcd for C46H44N2O6: C, 76.64; H, 6.15; N, 3.89. Found: C,
76.52; H, 6.04; N, 3.97.
25,26-Bis[(2-p yr id ylm eth yl)oxy]-27,28-cr ow n -4-ca lix[4]-
a r en e, Con e Con for m er (4b): 3% yield, mp 184-185 °C
(hexanes-Et2O); H NMR δ 3.05 and 4.32 (AX, J ) 13.5 Hz,
2 H), 3.11 and 4.99 (AX, J ) 13.2 Hz, 4 H), 3.14 and 4.39 (AX,
J ) 13.6 Hz, 2 H), 3.64-3.73 (m, 4 H), 3.80-3.90 (m, 4 H),
4.16 (ddd, J ) 11.0, 8.3, 2.7 Hz, 2 H), 4.28 (ddd, J ) 11.0, 3.8,
2.7 Hz, 2 H), 5.07 and 5.19 (ABq, J ) 12.6 Hz, 4 H), 6.56-
6.68 (m, 12 H), 7.19 (ddd, J ) 7.4, 4.9, 1.3 Hz, 2 H), 7.58 (td,
J ) 7.4, 1.8 Hz, 2 H), 7.66 (dt, J ) 7.4, 1.0 Hz, 2 H), 8.54 (ddd,
1
(20) Ouchi, M.; Inoue, Y.; Kanzaki, T.; Hakushi T. J . Org. Chem.
1984, 49, 1408.
(21) Widhalm, M.; Kalchhauser, H.; Ka¨hlig, H. Helv. Chim. Acta
1994, 77, 409.
(22) Kyba, E. P.; Gokel, G. W.; de J ong, F.; Koga, K.; Sousa, L. R.;
Siegel, M. G.; Kaplan, L.; Dotsevi, G.; Sogah, Y.; Cram D. J . J . Org.
Chem. 1977, 42, 4173.
(23) Yamamoto, H.; Sakaki, T.; Shinkai, S. Chem. Lett. 1994, 469.

9708 J . Org. Chem., Vol. 63, No. 26, 1998
Ferguson et al.
J ) 4.9, 1.8, 1.0 Hz, 2 H); 13C NMR δ 30.0, 30.9, 31.1 (×2) (t,
ArCH2Ar), 70.0, 70.6, 73.3 (t, OCH2CH2O), 77.5 (t, OCH2Py),
122.2, 122.4, 122.5, 123.3, 128.18, 128.25, 128.34, 128.4 (d, 3,5-
Py and ArH), 134.4, 134.5, 134.7, 135.9 (s, bridgehead-C), 136.2
30.9 (t, ArCH2Ar), 31.4 (q, C(CH3)3), 33.0, 33.8 (s, C(CH3)3),
69.7, 70.4, 70.5, 70.8, 73.1 (t, OCH2CH2O), 78.1 (t, OCH2Py),
122.3, 123.2 (d, 3,5-Py), 125.0, 125.1, 125.2, 125.3 (d, Ar), 133.5
(×2), 133.6, 134.0, (s, bridgehead-C), 136.5 (d, 4-Py), 144.7,
O), 158.3 (s, 2-Py); MS, m/z 1033 (MH+). Anal. Calcd for
C66H84N2O8: C, 76.71; H, 8.19; N, 2.71. Found: C, 76.53; H,
8.24; N, 2.66.
2
2
2
(d, 4-Py), 148.9 (d, 6-Py), 155.5, 156.0 (s, Csp -O), 157.9 (s,
144.8 (s, Csp -C(CH3)3), 148.6 (d, 6-Py), 152.7, 153.1 (s, Csp -
2-Py); MS, m/z 721 (MH+). Anal. Calcd for C46H44N2O6: C,
76.64; H, 6.15; N, 3.89. Found: C, 76.81; H, 6.38; N, 3.68.
5,11,17,23-Te t r a k is(1,1-d im e t h yle t h yl)-25,26-b is[(2-
p yr id ylm eth yl)oxy]-27,28-cr ow n -5-ca lix[4]a r en e, 1,2-Al-
ter n a te a n d Con e Con for m er s (3c) a n d (4c). Reaction
25,26-Bis[(2-p yr id ylm eth yl)oxy]-27,28-cr ow n -6-ca lix[4]-
a r en e, 1,2-Alter n a te Con for m er (3f): 51% yield, thick oil;
1H NMR δ 2.40-2.48 (m, 2 H), 3.08-3.15 (m, 2 H), 3.22, 3.32
(d, J ) 12.7 Hz, 1 H each), 3.46-3.71 (m, 16 H), 3.88 (pseudo-
s, 4 H), 4.28, 4.32 (d, J ) 12.7 Hz, 1 H each), 4.61 and 4.67
(ABq, J ) 13.7 Hz, 4 H), 6.14 (dt, J ) 7.5, 0.9 Hz, 2 H), 6.67
(t, J ) 7.5 Hz, 2 H), 6.72 (dd, J ) 7.5, 2.3 Hz, 2 H), 6.89 (td,
J ) 7.5, 1.9 Hz, 2 H), 6.95 (ddd, J ) 7.5, 4.8, 1.3 Hz, 2 H), 7.17
(dd, J ) 7.5, 2.3 Hz, 2H), 7.18 (dd, J ) 7.5, 1.7 Hz, 2 H), 7.34
(dd, J ) 7.5, 1.7 Hz, 2 H), 8.33 (ddd, J ) 4.8, 1.9, 0.9 Hz, 2 H);
13C NMR δ 29.2, 29.7, 37.8 (×2) (t, ArCH2Ar), 68.8, 70.3, 70.7,
70.9 (×2), (t, OCH2CH2O), 74.6 (t, OCH2Py), 121.1, 121.5,
122.5, 123.2, 128.4, 129.1, 129.5, 129.6 (d, 3,5-Py and Ar),
133.1, 133.2, 134.4, 135.3 (s, bridgehead-C), 136.0 (d, 4-Py),
t
of 1b with 2b and BuOK under standard conditions gave after
chromatography crown-5 conformers 3c (27% yield) and 4c
(45% yield).7
25,26-Bis[(2-p yr id ylm eth yl)oxy]-27,28-cr ow n -5-ca lix[4]-
a r en e, 1,2-Alter n a te Con for m er (3d ): 32% yield, mp 180-
181 °C (cyclohexane-CH2Cl2); 1H NMR δ 2.56 (dt, J ) 9.5,
6.5 Hz, 2 H), 3.24, 3.32 (d, J ) 12.5 Hz, 1 H each), 3.19-3.24
(m, 2 H), 3.47-3.75 (m, 12 H), 3.85 and 3.91 (ABq, J ) 16.7
Hz, 4 H), 4.26, 4.28 (d, J ) 12.5 Hz, 1 H each), 4.62 and 4.68
(ABq, J ) 14.0 Hz, 4 H), 6.17 (ddd, J ) 7.5, 1.4, 0.9 Hz, 2 H),
6.67 (t, J ) 7.3 Hz, 2 H), 6.71 (dd, J ) 7.3, 2.2 Hz, 2 H), 6.88
(td, J ) 7.5, 1.9 Hz, 2 H), 6.96 (ddd, J ) 7.5, 4.8, 1.4 Hz, 2 H),
7.00 (t, J ) 7.5 Hz, 2 H), 7.17 (dd, J ) 7.3, 2.2 Hz, 2 H), 7.23
(dd, J ) 7.5, 1.7 Hz, 2 H), 7.36 (dd, J ) 7.5, 1.7 Hz, 2 H), 8.34
(ddd, J ) 4.8, 1.9, 0.9 Hz, 2 H); 13C NMR δ 28.2, 29.7, 37.7
(×2) (t, ArCH2Ar), 69.3, 70.4, 70.6, 71.8 (t, OCH2CH2O), 74.6
(t, OCH2Py), 121.1, 121.5 (d, 3,5-Py), 122.5, 123.2, 128.5, 129.0,
129.6, 129.7 (d, Ar), 133.1, 133.3, 134.3, 135.1 (s, bridgehead-
2
147.9 (d, 6-Py), 155.4, 156.1 (s, Csp -O), 157.5 (s, 2-Py); MS,
m/z 809 (MH+). Anal. Calcd for C50H52N2O8: C, 74.24; H, 6.48;
N, 3.46. Found: C, 73.95; H, 6.76; N, 3.35.
25,26-Bis[(2-p yr id ylm eth yl)oxy]-27,28-cr ow n -6-ca lix[4]-
a r en e, Con e Con for m er (4f): 12%, thick oil; 1H NMR δ 3.05
and 4.58 (AX, J ) 13.5 Hz, 2 H), 3.12 and 4.39 (AX, J ) 13.3
Hz, 4 H), 3.17 and 4.34 (AX, J ) 13.5 Hz, 2 H), 3.5-3.7 (m, 12
H), 3.82-3.89 (m, 4 H), 4.13 (t, J ) 6.4 Hz, 4 H), 5.03 and
5.12 (ABq, J ) 13.5 Hz, 4 H), 6.56-6.66 (m, 12 H), 7.19 (ddd,
J ) 7.5, 4.9, 1.2 Hz, 2 H), 7.61 (td, J ) 7.5, 1.8 Hz, 2 H), 7.75
(dt, J ) 7.5, 0.9 Hz, 2 H), 8.53 (ddd, J ) 4.9, 1.8, 0.9 Hz, 2 H);
13C NMR δ 30.9, 31.0 (t, ArCH2Ar), 70.1, 70.5, 70.7, 70.8, 72.9
(t, OCH2CH2O), 77.6 (t, OCH2Py), 122.2, 122.46, 122.53, 123.5,
128.21, 128.24, 128.4 (d, 3,5-Py and Ar), 134.7, 134.8, 134.9,
135.2 (s, bridgehead-C), 136.3 (d, 4-Py), 148.8 (d, 6-Py), 155.5,
2
C), 136.0 (d, 4-Py), 147.9 (d, 6-Py), 155.6, 156.0 (s, Csp -O),
157.6 (s, 2-Py); MS, m/z 765 (MH+). Anal. Calcd for
C
48H48N2O7: C, 75.37; H, 6.33; N, 3.66. Found: C, 75.18; H,
6.11; N, 3.81.
25,26-Bis[(2-p yr id ylm eth yl)oxy]-27,28-cr ow n -5-ca lix[4]-
a r en e, Con e Con for m er (4d ): 28% yield, mp 150-151 °C
1
(hexanes-Et2O); H NMR δ 3.02, 3.14, 3.15 (d, J ) 13.5 Hz,
ratio 1:2:1, 4 H), 3.60-3.67 (m, 8 H), 3.95-4.03 (m, 6 H), 4.19-
4.23 (m, 2 H), 4.28, 4.41, 4.61 (d, J ) 13.5 Hz, ratio 1:2:1, 4
H), 5.08 and 5.15 (ABq, J ) 12.7 Hz, 4 H), 6.56-6.66 (m, 12
H), 7.18 (ddd, J ) 7.5, 4.9, 1.2 Hz, 2 H), 7.60 (td, J ) 7.5, 1.8
Hz, 2 H), 7.81 (dt, J ) 7.5, 0.9 Hz, 2 H), 8.51 (ddd, J ) 4.9,
1.8, 0.9 Hz, 2 H); 13C NMR δ 29.7, 30.9, 31.1 (t, ArCH2Ar),
70.2, 70.3, 71.1, 73.3 (t, OCH2CH2O), 77.5 (t, OCH2Py), 122.3,
122.4 (×2), 123.3, 128.2, 128.37, 128.41, 128.44 (d, 3,5-Py and
Ar), 134.6, 134.7, 134.8, 135.5 (s, bridgehead-C), 136.4 (d, 4-Py),
+
2
156.1 (s, Csp -O), 158.1 (s, 2-Py); MS, m/z 809 (MH ). Anal.
Calcd for C50H52N2O8: C, 74.24; H, 6.48; N, 3.46. Found: C,
74.43; H, 6.67; N, 3.41.
5,11,17,23-Te t r a k is(1,1-d im e t h yle t h yl)-25,26-b is[(2-
p yr id ylm eth yl)oxy]-27,28-(2,2′-bin a p h th yl-cr ow n -4-ca lix-
[4]a r en e, Con e Con for m er (4g): 45% yield, mp 280-282
°C (MeOH-Et2O); 1H NMR δ 0.98, 1.00, 1.14 and 1.15 (s,
C(CH3)3, 9 H each), 2.87 and 3.85 (AX, J ) 12.4 Hz, ArCH2Ar,
2 H), 2.90 and 4.37 (AX, J ) 12.4 Hz, ArCH2Ar, 2 H), 3.17
and 4.39 (AX, J ) 12.7 Hz, ArCH2Ar, 2 H), 3.22 and 4.54 (AX,
J ) 12.6 Hz, ArCH2Ar, 2 H), 3.74 (m, OCH2CH2O, 1 H), 4.03
(t, J ) 6.7 Hz, OCH2CH2O, 2 H), 4.20 (m, OCH2CH2O, 2 H),
4.4-4.5 (m, OCH2CH2O, 3 H), 4.75 and 5.11 (ABq, J ) 12.7
Hz, OCH2Py, 2 H), 4.93 and 4.98 (ABq, J ) 12.0 Hz, OCH2-
Py′, 2 H), 6.63 (td, J ) 7.5, 1.9 Hz, 4-Py′H, 1 H), 6.64 (d, J )
2.4 Hz, ArH, 1 H), 6.69 (d, J ) 2.4 Hz, ArH, 2 H), 6.73 (ddd,
J ) 7.5, 4.9, 1.3 Hz, 5-Py′H, 1 H), 6.74, 6.81, 6.84, 6.92, 6.96
(d, J ) 2.4 Hz, ArH, 1 H each), 7.00 (d, J ) 8.9 Hz, BinaphH,
1 H), 7.08-7.36 (m, 5-PyH, 3-Py′H, and BinaphH, 10 H), 7.47
(td, J ) 7.5, 1.9 Hz, 4-PyH, 1 H), 7.61 (d, J ) 8.9 Hz, BinaphH,
1 H), 7.73 (dt, J ) 8.0, 0.6 Hz, BinaphH, 1 H), 7.84 (ddd, J )
7.5, 1.9, 0.9 Hz, 3-PyH, 1 H), 7.92 (d, J ) 8.9 Hz, BinaphH, 1
H), 8.29 (ddd, J ) 4.9, 1.9, 0.9 Hz, 6-PyH, 1 H), 8.69 (ddd, J )
4.9, 1.9, 0.9 Hz, 6-Py′H, 1 H); 13C NMR δ 30.8, 30.9, 31.0, 31.2
(t, ArCH2Ar), 31.3 (×2), 31.46, 31.51 (q, (C(CH3)3), 33.74, 33.77,
33.88, 33.91 (s, (C(CH3)3), 68.7, 69.3, 71.8, 72.8 (t, OCH2CH2),
78.0, 78.5 (t, OCH2Py), 114.8, 117.7 (d), 119.0, 121.7 (s), 122.0,
122.7, 123.3, 123.4, 123.68, 123.73, 124.8, 125.06, 125.10,
125.15 (×2), 125.2 (×3), 125.4, 125.8, 126.27, 126.32, 127.8,
127.9, 129.11 (d), 129.15 (s), 129.2 (d), 129.8, 132.8, 132.9,
133.0, 133.1, 133.8, 134.2, 134.3 (×2), 134.4, 134.6 (s), 136.2,
2
148.7 (d, 6-Py), 155.6, 156.1 (s, Csp -O), 158.1 (s, 2-Py); MS,
m/z 765 (MH+). Anal. Calcd for C48H48N2O7: C, 75.37; H, 6.33;
N, 3.66. Found: C, 75.58; H, 6.54; N, 3.85.
5,11,17,23-Te t r a k is(1,1-d im e t h yle t h yl)-25,26-b is[(2-
p yr id ylm eth yl)oxy]-27,28-cr ow n -6-ca lix[4]a r en e, 1,2-Al-
ter n a te Con for m er (3e): 21% yield; mp 134-137 °C
(cyclohexane-CH2Cl2); 1H NMR δ 1.11, 1.37 (s, 18 H each),
2.55 (dt, J ) 9.7, 7.1 Hz, 2 H), 3.09-3.16 (m, 2 H), 3.16, 3.21
(d, J ) 12.2 Hz, 1 H each), 3.39-3.63 (m, 16 H), 3.84 and 3.90
(ABq, J ) 17.2 Hz, 4 H), 4.17, 4.46 (d, J ) 12.2 Hz, 1 H each),
4.54 and 4.59 (ABq, J ) 13.9 Hz, 4 H), 6.14 (dt, J ) 7.6, 0.9
Hz, 2 H), 6.76 and 7.19 (AX, J ) 2.5 Hz, 4 H), 6.78 (td, J )
7.6, 1.9 Hz, 2 H), 6.87 (ddd, J ) 7.6, 4.8, 1.3 Hz, 2 H), 7.12
and 7.37 (AX, J ) 2.5 Hz, 4 H), 8.28 (ddd, J ) 4.8, 1.9, 0.9 Hz,
2 H); 13C NMR δ 28.8, 29.7, 38.8 (×2) (t, ArCH2Ar), 31.4, 31.7
(q, C(CH3)3), 33.9, 34.1 (s, C(CH3)3), 68.1, 70.1, 70.3, 70.5, 70.9
(t, OCH2CH2O), 74.4 (t, OCH2Py), 121.11, 121.15 (d, 3,5-Py),
124.6, 125.6, 125.7, 126.0 (d, Ar), 132.0, 132.5, 133.6, 134.8 (s,
2
bridgehead-C), 136.3 (d, 4-Py), 144.5, 145.1 (s, Csp -C(CH3)3),
2
147.8 (d, 6-Py), 153.1, 153.6 (s, Csp -O), 158.0 (s, 2-Py); MS,
m/z 1033 (MH+). Anal. Calcd for C66H84N2O8: C, 76.71; H, 8.19;
N, 2.71. Found: C, 76.95; H, 8.30; N, 2.61.
5,11,17,23-Te t r a k is(1,1-d im e t h yle t h yl)-25,26-b is[(2-
p yr id ylm eth yl)oxy]-27,28-cr ow n -6-ca lix[4]a r en e, Con e
Con for m er (4e): 35% yield; mp 270-271 °C (cyclohexane-
2
136.7 (d, 4-Py), 144.6, 144.8, 144.9, 145.1 (s, Csp -C(CH3)3),
1
CH2Cl2); H NMR δ 1.08, 1.09 (s, 18 H each), 3.10, 3.12 (d, J
147.9, 149.1 (d, 6-Py), 152.5, 152.6, 153.24, 153.26, 154.0, 155.0
+
2
) 12.5 Hz, ratio 3:1, 4 H), 3.48-4.08 (m, 20 H), 4.34, 4.43,
4.51 (d, J ) 12.5 Hz, ratio 2:1:1, 4 H), 5.01 (pseudo-s, 4 H),
6.80-6.83 (m, 8 H), 7.17 (ddd, J ) 7.5, 4.9, 1.2 Hz, 2 H), 7.59
(td, J ) 7.5, 1.8 Hz, 2 H), 7.85 (dt, J ) 7.5, 0.9 Hz, 2 H), 8.53
(ddd, J ) 4.9, 1,8, 0.9 Hz, 2 H); 13C NMR δ 30.7, 30.8 (×2),
(s, Csp -O), 157.9 and 158.0 (s, 2-Py); MS, m/z 1169 (MH ).
Anal. Calcd for C80H84N2O6: C, 82.16; H, 7.24; N, 2.40.
Found: C, 82.40; H, 7.11; N, 2.35.
25,26-Bis[(2-p yr id ylm e t h yl)oxy]-27,28-(2,2′-b in a p h -
th ylcr own -4)-calix[4]ar en e, 1,2-Alter n ate Con for m er (3h ):

1,2-Bridged Calix[4]arene Mono- and Biscrowns
J . Org. Chem., Vol. 63, No. 26, 1998 9709
36% yield, mp 277-279 °C (MeOH); 1H NMR δ 2.24 (ddd, J )
10.2, 7.7, 6.1 Hz, OCH2CH2O, 1 H), 2.91 (ddd, J ) 10.7, 7.7,
4.3 Hz, OCH2CH2O, 1 H), 3.10 (dt, J ) 11.6, 5.8 Hz, OCH2-
CH2O, 1 H), 3.26-3.33 (m, OCH2CH2O, 1 H), 3.29 and 4.41
(AX, J ) 12.4 Hz, ArCH2Ar, 2 H), 3.36 and 4.30 (AX, J ) 12.8
Hz, ArCH2Ar, 2 H), 3.68-3.96 (m, ArCH2Ar and OCH2CH2O,
6 H), 4.14-4.22 (m, OCH2CH2O, 1 H), 4.31-4.39 (m, OCH2-
CH2O, 1 H), 4.43 and 4.70 (ABq, J ) 14.6 Hz, OCH2Py, 2 H),
4.56 and 4.77 (ABq, J ) 12.9 Hz, OCH2Py′, 2 H), 5.62 (dt, J )
7.5, 0.9 Hz, 3-PyH, 1 H), 6.50-6.59 (m, 5 H), 6.75 (t, J ) 7.5
Hz, ArH, 1 H), 6.84-7.25 (m, 17 H), 7.30 (d, J ) 9.0 Hz, 1 H),
7.39 (ddd, J ) 8.1, 6.8, 1.3 Hz, 1 H), 7.45 (dd, J ) 7.8, 1.4 Hz,
1 H), 7.60 (dt, J ) 7.5, 1.2 Hz, 1 H), 7.78 (dt, J ) 8.2, 0.8 Hz,
1 H), 7.85 (d, J ) 9.4 Hz, 1 H), 7.99 (d, J ) 8.0 Hz, 1 H), 8.10
(d, J ) 8.5 Hz, 1 H), 8.30 (ddd, J ) 4.8, 1.8, 0.9 Hz, 6-Py′H, 1
H), 8.33 (dt, J ) 4.8, 1.4 Hz, 6-PyH, 1 H); 13C NMR δ 28.1,
29.7 37.7, 38.2 (t, ArCH2Ar), 68.3, 68.5, 69.2, 72.5 (t, OCH2-
CH2O), 73.4, 75.8 (t, OCH2Py), 113.7 (d), 119.2 (s), 120.1, 120.6,
121.0 (d), 121.5 (s), 121.7, 121.9, 122.1, 123.1, 123.3, 123.4,
123.8, 124.0, 125.6, 125.9, 126.3, 127.7, 128.0, 128.1, 128.4,
128.76, 128.80, 128.93 (d), 128.96 (s), 129.0, 129.10, 129.16,
129.21 (d), 130.0 (s), 130.3 (d), 131.9, 132.3, 133.4, 133.6, 133.8,
134.16, 134.24, 135.0 (s), 135.57, 135.61 (d), 136.0 (s), 136.2,
147.4, 148.3 (d), 153.7, 154.8, 155.4, 155. 5, 156.7, 157.01,
5,11,17,23-Te t r a k is(1,1-d im e t h yle t h yl)-25,26-b is[(2-
p yr id ylm eth yl)oxy]-27,28-(2,2′-bin a p h th ylcr ow n -6)ca lix-
[4]a r en e, Con e Con for m er (4i): 43% yield; mp 156-157
1
°C (CHCl3-MeOH); H NMR δ 1.06, 1.08, 1.09, 1.12 (s, 9 H
each), 3.05, 3.07, 3.11, 3.13 (d, J ) 12.5 Hz, 1 H each), 3.24-
4.14 (m, 16 H), 4.27, 4.41, 4.44, 4.47 (d, J ) 12.5 Hz, 1 H each),
4.93 and 5.01 (ABq, J ) 12.9 Hz, 2 H), 4.99 and 5.19 (ABq, J
) 12.6 Hz, 2 H), 6.77-6.83 (m, 8 H), 6.92 (ddd, J ) 7.5, 4.8,
1.2 Hz, 1 H), 7.03-7.13 (m, 3 H), 7.17 (ddd, J ) 8.4, 6.7, 1.4
Hz, 1 H), 7.21 (ddd, J ) 8.4, 6.7, 1.4 Hz, 1 H), 7.24 (d, J ) 9.0
Hz, 1 H), 7.29 (ddd, J ) 8.1, 6.7, 1.3 Hz, 1 H), 7.32 (ddd, J )
8.1, 6.7, 1.3 Hz, 1 H), 7.39 (td, J ) 7.5, 1.8 Hz, 1 H), 7.43 (td,
J ) 7.5, 1.8 Hz, 1 H), 7.45 (d, J ) 9.0 Hz, 1 H), 7.68 (dt, J )
7.5, 0.9 Hz, 1 H), 7.82 (bd, J ) 8.8 Hz, 1 H), 7.84 (d, J ) 8.8
Hz, 1 H), 7.85 (d, J ) 8.5 Hz, 1 H), 7.88 (dt, J ) 7.5, 0.9 Hz,
1 H), 7.89 (d, J ) 8.8 Hz, 1 H), 8.46 (ddd, J ) 4.8, 1.8, 0.9 Hz,
1 H), 8.48 (ddd, J ) 4.8, 1.8, 0.9 Hz, 1 H); 13C NMR δ 30.7,
30.8, 30.96, 31.05, 31.41 (×2), 31.43, 31.45, 33.80, 33.83, 33.85,
33.87, 68.9, 69.2, 69.3, 69.4, 69.9, 70.0, 73.07, 73.12 77.97,
78.02, 115.4, 116.3, 120.1, 120.3, 122.2, 122.3, 123.1, 123.5,
123.6, 124.89, 124.94, 125.0, 125.16, 125.20, 125.24, 125.27,
125.38, 125.40, 125.48, 126.1, 126.2, 127.82, 127.84, 129.1,
129.2, 129.3, 129.4, 133.40, 133.44, 133.50, 133.7, 133.89,
133.95, 134.0, 134.1, 136.2, 136.6, 144.67, 144.74, 144.79,
144.84, 148.5, 148.6, 152.6, 152.77, 152.80, 153.3, 154.4, 154.6,
158.3, 158.4; MS, m/z 1257 (MH+). Anal. Calcd for
+
2
157.03, 158.0 (s, Csp -O, 2-Py and 2-Py′); MS, m/z 945 (MH ).
Anal. Calcd for C64H52N2O6: C, 81.32; H, 5.55; N, 2.97.
Found: C, 81.23; H, 5.40; N, 2.88.
C
84H92N2O8: C, 80.22; H, 7.37; N, 2.23. Found: C, 80.46; H,
7.48; N, 2.16.
25,26-Bis[(2-p yr id ylm e t h yl)oxy]-27,28-(2,2′-b in a p h -
th ylcr ow n -4)-ca lix[4]a r en e, Con e Con for m er (4h ): 21%
yield, mp 268-269 °C (MeOH-Et2O); H NMR δ 2.78, 2.93,
25,26-Bis[(2-p yr id ylm e t h yl)oxy]-27,28-(2,2′-b in a p h -
th ylcr ow n -6)-ca lix[4]a r en e, 1,2-Alter n a te Con for m er (3j):
28% yield, mp 145-147 °C (hexane-CH2Cl2); 1H NMR δ 2.08-
2.16 (m, 1 H), 2.26-2.34 (m, 1 H), 2.88-3.00 (m, 2 H), 3.18-
3.55 (m, 10 H), 3.83 (bs, 4 H), 3.99-4.10 (m, 3 H), 4.259, 4.264
(d, J ) 12.5 and 12.8 Hz, respectively, 1 H each), 4.22-4.29
(m, 1 H), 4.60 and 4.66 (ABq, J ) 14.2 Hz, 2 H), 4.63 and 4.64
(ABq, J ) 13.1 Hz, 2 H), 6.11, 6.18 (dt, J ) 7.7, 0.9 Hz, 1 H
each), 6.66-6.98 (m, 10 H), 7.06-7.35 (m, 12 H), 7.36, 7.52
(d, J ) 9.0 Hz, 1 H each), 7.74 (dd, J ) 7.6, 1.0 Hz, 1 H), 7.76
(d, J ) 9.3 Hz, 1H), 7.89 (dt, J ) 8.0, 0.7 Hz, 1 H), 8.01 (d, J
) 9.3 Hz, 1 H), 8.34 (ddd, J ) 4.8, 1.9, 0.9 Hz, 2 H); 13C NMR
δ 28.2, 29.3, 37.6, 37.8 (t, ArCH2Ar), 68.4, 68.6, 68.9, 69.0, 69.4,
69.5, 70.5, 71.2 (t, OCH2CH2O), 74.5, 74.7 (t, OCH2Py), 115.2,
116.4 (d), 120.2 (s), 121.0, 121.1, 121.4, 121.5, 122.6 (×2), 123.0,
123.3, 123.5, 123.6, 125.36, 125.44, 126.1, 126.3, 127.8, 127.9,
128.4, 128.5, 129.0, 129.23, 129.26 (×2), 129.30 (d), 129.4 (s),
129.5, 129.6, 129.8 (d), 133.06, 133.14, 133.20, 133.3, 133.9,
134.1, 134.2, 134.5, 135.3 (×2) (s), 135.92, 135.97 (d, 4-Py and
4-Py′), 147.86, 147.95 (d, 6-Py and 6-Py′), 154.2, 154.6, 155.2,
1
3.19, 3.21 (d, J ) 13.4 Hz, 1 H each), 3.92-4.55 (m, 8 H), 3.72,
4.18, 4.46, 4.51 (d, J ) 13.4 Hz, 1 H each), 4.79 and 4.97 (ABq,
J ) 12.1 Hz, 2 H), 4.98 and 5.01 (ABq, J ) 11.6 Hz, 2 H),
6.42-6.85 (m, 13 H), 7.01 (ddd, J ) 7.6, 1.8, 0.9 Hz, 2 H), 7.09
(d, J ) 9.0 Hz, 1 H), 7.15 (d, J ) 9.1 Hz, 2 H), 7.11-7.31 (m,
6 H), 7.54 (d, J ) 9.0 Hz, 1 H), 7.56-7.71 (m, 3 H), 7.84 (d, J
) 8.0 Hz, 1 H), 7.91 (d, J ) 9.0 Hz, 1 H), 8.27 (ddd, J ) 4.9,
1.8, 0.9 Hz, 1 H), 8.63 (ddd, J ) 4.9, 1.8, 0.9 Hz, 1 H); 13C
NMR δ 30.8 (×2), 31.1, 31.2 (t, ArCH2Ar), 69.1, 69.3, 71.9, 72.1
(t, OCH2CH2O), 77.5, 78.2 (t, OCH2Py), 115.2, 117.8 (d,), 119.0
(s), 122.1, 122.2 (d), 122.4 (s), 122.51, 122.54, 122.6, 122.8,
123.3, 123.6, 123.9, 124.1, 124.9, 125.26, 125.34, 126.4, 127.8,
127.87, 127.90, 128.0, 128.2, 128.3, 128.4, 128.5, 128.6, 129.0
(d), 129.2 (s), 129.3, 129.4, (d), 130.0, 133.9, 134.1, 134.2,
134.27, 134.32, 135.0, 135.2, 135.5, 135.6 (s), 136.0, 136.5 (d,
4-Py and 4-Py′), 147.9, 149.3 (d, 6-Py and 6-Py′), 153.7, 154.9,
2
155.3, 155.4, 155.7, 156.0 (s, Csp -O), 157.0 and 157.5 (s, 2-Py
and 2-Py′); MS, m/z 945 (MH+). Anal. Calcd for C64H52N2O6:
C, 81.32; H, 5.55; N, 2.97. Found: 81.48; H, 5.31; N, 2.92.
5,11,17,23-Te t r a k is(1,1-d im e t h yle t h yl)-25,26-b is[(2-
p yr id ylm eth yl)oxy]-27,28-(2,2′-bin a p h th yl-cr ow n -6)ca lix-
[4]a r en e, 1,2-Alter n a te Con for m er (3i): 6% yield after
chromatographic purification on preparative TLC plates
(CHCl3-AcOEt, 7:1; three elutions); mp 138-140 °C (MeOH-
CH2Cl2); 1H NMR δ 1.06, 1.17, 1.29, 1.36 (s, 9 H each), 2.55-
2.64, 2.79-2.87, 2.95-3.02 (m, 1 H each), 3.05-3.48 (m, 10
H), 3.70-4.16 (m, 9 H), 4.18 (d, J ) 12.3 Hz, 1 H), 4.44 and
4.66 (ABq, J ) 14.7 Hz, 2 H), 4.46 (d, J ) 12.5 Hz, 1 H), 4.51
and 4.77 (ABq, J ) 13.6 Hz, 2 H), 5.93 (dt, J ) 7.9, 0.9 Hz, 1
H), 6.48-6.54 (m, 2 H), 6.67 (d, J ) 2.4 Hz, 1 H), 6.81-7.35
(m, 18 H), 7.55 (d, J ) 8.7 Hz, 1 H), 7.66 (dd, J ) 8.4, 0.8 Hz,
1 H), 7.85 (d, J ) 7.7 Hz, 1 H), 7.93 (d, J ) 8.7 Hz, 1 H), 8.31
(dt, J ) 4.7, 0.9 Hz, 2 H); 13C NMR δ 28.9, 30.4 (t, ArCH2Ar),
31.4, 31.58, 31.64, 31.66 (q, C(CH3)3), 33.89, 33.93, 34.07, 34.14
(s, C(CH3)3), 38.6, 38.8 (t, ArCH2Ar), 67.2, 67.9, 68.8, 68.9, 69.0,
69.2, 69.3, 71.3 (t, OCH2CH2O), 73.7, 74.9 (t, OCH2Py), 114.4,
116.7 (d), 119.8, 120.5, (s), 120.9, 121.4, 121.6 (d, 3,5-Py and
3,5-Py′), 123.4, 124.6, 125.3, 125.4, 125.5, 125.7, 125.8, 125.90,
125.94, 126.0, 126.3, 126.4, 127.8 (d), 129.0 (s), 129.1, 129.2
(d), 129.4, 131.4, 131.8, 132.8, 133.18, 133.25, 133.87, 133.90,
134.06, 134.14, 135.5(s), 136.3, 137.1 (d, 4-Py and 4-Py′), 144.3,
144.9, 145.0, 145.3 (s), 147.2, 147.9 (d, 6-Py and 6-Py′), 153.1,
153.2, 153.76, 153.83, 154.3, 154.5 (s), 157.6 and 158.3 (s, 2-Py
and 2-Py′); MS, m/z 1257 (MH+). Anal. Calcd for C84H92N2O8:
C, 80.22; H, 7.37; N, 2.23. Found: C, 80.54; H, 7.65; N, 2.12.
2
155.4, 156.06, 156.14 (Csp -O), 157.5 and 157.6 (2-Py and
2-Py′); MS, m/z 1033 (MH+). Anal. Calcd for C68H60N2O8: C,
79.04; H, 5.86; N, 2.71. Found: C, 79.13; H, 6.01; N, 2.58.
25,26-Bis[(2-p yr id ylm e t h yl)oxy]-27,28-(2,2′-b in a p h -
th ylcr ow n -6)-ca lix[4]a r en e, Con e Con for m er (4j): 12%
yield, mp 113-115 °C (EtOH); 1H NMR δ 3.02, 3.08, 3.14, 3.17
(d, J ) 13.5 Hz, 1 H each), 3.37-3.57 (m, 4 H), 3.74 (bt, J )
5.7 Hz, 2 H), 3.84-4.15 (m, 10 H), 4.30, 4.33, 4.46, 4.54 (d, J
) 13.5 Hz, 1 H each), 5.00 and 5.07 (ABq, J ) 12.6 Hz, 2 H),
5.10 and 5.21 (ABq, J ) 12.3 Hz, 2 H), 6.55-6.71 (m, 12 H),
7.03 (ddd, J ) 7.5, 4.9, 1.2 Hz, 1 H), 7.06-7.34 (m, 7 H), 7.17
(d, J ) 9.0 Hz, 1 H), 7.37 (td, J ) 7.5, 1.8 Hz, 1 H), 7.43 (d, J
) 9.0 Hz, 1 H), 7.49 (td, J ) 7.5, 1.8 Hz, 1 H), 7.67 (ddd, J )
7.5, 1.8, 0.9 Hz, 2 H), 7.74 (d, J ) 8.8 Hz, 1 H), 7.79-7.83 (m,
2 H), 7.89 (d, J ) 8.8 Hz, 1 H), 8.47 (ddd, J ) 4.9, 1.8, 0.9 Hz,
1 H), 8.49 (ddd, J ) 4.9, 1.8, 0.9 Hz, 1 H); 13C NMR δ 30.9
(×3), 31.1 (t, ArCH2Ar), 69.1, 69.2, 69.4, 69.5, 70.1, 70.4, 72.9,
73.0 (t, OCH2CH2O), 77.4, 77.5 (t, OCH2Py), 115.4, 116.0 (d),
120.2 (s), 122.3 122.41, 122.45, 122.48, 122.53, 123.2, 123.5,
123.7, 125.3, 125.5, 126.16, 126.23, 127.80, 127.84, 128.13,
128.18, 128.3, 128.39, 128.41, 128.5, 129.1, 129.28 (d), 129.21,
129.33, 134.01, 134.06, 134.57, 134.65, 134.71, 134.85, 134.94,
134.96, 135.28 (s), 136.2, 136.3 (d, 4-Py and 4-Py′), 148.8, 148.9
(d, 6-Py and 6-Py′), 154.3, 154.4, 155.38, 155.43, 156.0 (×2)
2
(Csp -O), 157.88 and 157.93 (2-Py and 2-Py′); MS, m/z 1033
(MH+). Anal. Calcd for C68H60N2O8: C, 79.04; H, 5.86; N, 2.71.
Found: C, 78.84; H, 5.96; N, 2.77.

9710 J . Org. Chem., Vol. 63, No. 26, 1998
Ferguson et al.
Rea ction of 5 w ith 2a -c. Diol 5 (0.269 g, 0.5 mmol) was
(m, 12 H); 13C NMR δ 29.8, 30.5, 31.0 (×2) (t, ArCH2Ar), 70.3,
70.5, 70.8, 71.4, 73.37, 73.40 (t, OCH2), 122.2, 122.3, 128.07,
128.13, 128.26, 128.33 (d, Ar), 134.5, 134.7, 135.1, 135.7 (s,
reacted with tri- to pentaethylene glycol ditosylate (1.1 equiv)
t
and BuOK (0.123 g, 1.1 mmol) in dry toluene, by following
2
the general procedure. Usual workup, followed by column
chromatography (SiO2, hexane-AcOEt, 75:25 to 0:100, v/v)
gave in order the relevant 1,2-alternate and cone biscrown
conformers. Further details are given for the individual
compounds.
bridgehead-C), 156.0 and 156.2 (s, Csp -O); MS, m/z 697
(MH+). Anal. Calcd for C42H48O9: C, 72.39; H, 6.94. Found:
C, 72.16; H, 7.15.
25,26-Cr ow n -4-27,28-cr ow n -6-ca lix[4]a r en e, 1,2-Alter -
1
n a te Con for m er (6c): 45% yield, thick oil; H NMR δ 2.62
25,26-27,28-Biscr ow n -4-ca lix[4]a r en e, 1,2-Alt er n a t e
Con for m er (6a ): 25% yield; mp 245-247 °C (MeOH), 1H NMR
δ 2.80 (ddd, J ) 10.5, 5.6, 4.7 Hz, OCH2CH2O, 4 H), 3.19 and
4.34 (AX, J ) 12.3 Hz, ArCH2Ar, 4 H), 3.21 (ddd, J ) 10.5,
7.2, 5.6 Hz, OCH2CH2O, 4 H), 3.41-3.62 (m, OCH2CH2O, 12
H), 3.71 (ddd, J ) 8.7, 7.2, 5.6 Hz, OCH2CH2O, 4 H), 3.90 (s,
ArCH2Ar, 4 H), 6.94 (t, J ) 7.5 Hz, ArH, 4 H), 7.08 and 7.20
(2dd, J ) 7.5, 1.8 Hz, ArH, 8 H); 13C NMR δ 28.4 and 38.1 (t,
ArCH2Ar), 68.6, 70.1, 70.4 (t, OCH2), 122.5, 128.9, 129.1 (d),
(dt, J ) 10.0, 7.0 Hz, 2 H), 2.80 (ddd, J ) 10.4, 5.7, 4.6 Hz, 2
H), 3.12-3.28 (m, 4 H), 3.18, 3.19 (d, J ) 12.5 Hz, 1 H each),
3.43-3.75 (m, 24 H), 3.87 and 3.94 (ABq, J ) 16.6 Hz, 4 H),
4.27, 4.34 (d, J ) 12.5 Hz, 1 H each), 6.90, 6.93 (t, J ) 7.5 Hz,
2 H each), 7.08, 7.11, 7.16, 7.17 (dd, J ) 7.5, 1.7 Hz, 2 H each);
13C NMR δ 28.5, 28.7 and 37.9 (×2) (t, ArCH2Ar), 68.5, 69.2,
70.0, 70.4, 70.48, 70.53, 70.7, 70.8 (t, OCH2), 122.4, 122.6, 128.8
(×2), 129.0, 129.4 (d, Ar), 132.9 (×2), 134.9, 135.0 (s, bridgehead-
+
2
C), 155.5 and 155.7 (s, Csp -O); MS, m/z 741 (MH ). Anal.
2
133.0, 135.0 (s, bridgehead-C), 155.5 (s, Csp -O); MS, m/z 653
Calcd for C44H52O10: C, 71.32; H, 7.08. Found: C, 71.06; H,
7.24.
(MH+). Anal. Calcd for C40H44O8: C, 73.60; H, 6.79. Found:
C, 73.42; H, 6.70.
25,26-Cr ow n -4-27,28-cr ow n -6-ca lix[4]a r en e, Con e Con -
1
25,26-27,28-Biscr own -4-calix[4]ar en e, Con e Con for m er
(7a ): 35% yield; mp 233-235 °C (MeCN) (lit.9 mp 234-236
°C); 1H NMR δ 3.11 and 4.97 (AX, J ) 12.9 Hz, 4 H), 3.22 and
4.35 (AX, J ) 13.3 Hz, 4 H), 3.7-3.9 (m, 20 H), 4.20 (ddd, J )
10.7, 8.1, 2.9 Hz, 2 H), 4.36 (m, 2 H), 6.59 (dd, J ) 8.2, 6.4 Hz,
4 H), 6.67 (m, 8 H).
for m er (7c): 22% yield, thick oil; H NMR δ 3.11 and 5.00,
3.16 and 4.54, 3.18 and 4.38 (3AX, J ) 13.2 Hz, ratio 1:1:2, 8
H), 3.64-4.35 (m, 30 H), 6.56-6.69 (m, 12 H); 13C NMR δ 29.8,
29.9 and 31.0 (×2) (t, ArCH2Ar), 70.2, 70.3, 70.6, 70.86, 70.94,
70.96, 73.1, 73.4 (t, OCH2), 122.23, 122.26, 128.13, 128.16,
128.24, 128.29 (d, Ar), 134.6, 134.9, 135.0, 135.7 (s, bridgehead-
+
2
25,26-Cr ow n -4-27,28-cr ow n -5-ca lix[4]a r en e, 1,2-Alter -
n a te Con for m er (6b): 30% yield; mp 189-191 °C (MeOH),
1H NMR δ 2.74-2.85 (m, 4 H), 3.19 (d, J ) 12.5 Hz, 2 H),
3.22-3.31 (m, 4 H), 3.46-3.74 (m, 20 H), 3.86 and 3.95 (ABq,
J ) 16.6 Hz, 4 H), 4.22 and 4.34 (2d, J ) 12.5 Hz, 2 H), 6.91
and 6.93 (2t, J ) 7.5 Hz, 4 H), 7.09 (dd, J ) 7.5, 1.9 Hz, 2 H),
7.16 (d, J ) 7.5 Hz, 4 H), 7.17 (dd, J ) 7.5, 1.9 Hz, 2 H); 13C
NMR δ 28.5, 28.8 and 37.9 (×2) (t, ArCH2Ar), 68.6, 69.7, 70.0,
70.4, 70.5, 70.6, 71.4 (t, OCH2), 122.4, 122.6, 128.7, 128.9,
129.3, 129.4 (d, Ar), 132.9, 133.0, 134.8, 135.0 (s, bridgehead-
C), 156.0 and 156.3 (s, Csp -O); MS, m/z 741 (MH ). Anal.
Calcd for C44H52O10: C, 71.32; H, 7.08. Found: C, 70.94; H,
7.36.
Ack n ow led gm en t . The Italian authors thank
M.U.R.S.T. (Ministero dell’Universita` e della Ricerca
Scientifica e Tecnologica) for financial support of this
work.
Su p p or tin g In for m a tion Ava ila ble: Atomic coordinates,
displacement parameters, and molecular geometry for 6a (11
pages). This material is contained in libraries on microfiche,
immediately follows this article in the microfilm version of this
journal, and can be ordered from the ACS; see any current
masthead page for ordering information.
+
2
C), 155.5 and 155.9 (s, Csp -O); MS, m/z 697 (MH ). Anal.
Calcd for C42H48O9: C, 72.39; H, 6.94. Found: C, 72.12; H,
6.78.
25,26-Cr ow n -4-27,28-cr ow n -5-ca lix[4]a r en e, Con e Con -
1
for m er (7b): 55% yield; mp 208-210 °C (MeOH), H NMR δ
3.11 and 4.99, 3.13 and 4.54, 3.20 and 4.38 (3AX, J ) 13.0-
13.3 Hz, ratio 1:1:2, 8 H), 3.67-4.36 (m, 28 H), and 6.56-6.68
J O9810516