J . Org. Chem. 1997, 62, 1899-1902
1899
carbonate (276 g, 2.00 mol), sodium iodide (6.00 g, 0.040 mol),
and absolute ethanol (1.50 L) were added to a 3 L three-necked
round-bottomed flask. The mixture was allowed to reflux for
24 h under argon, cooled to ambient temperature, and filtered
to remove solid material. The solvent was evaporated under
reduced pressure to give a brown liquid (301 g, 98%). 1H NMR
(CDCl3): δ 7.12 (dd, 4H, J ) 7.8, 1.0 Hz); 6.81 (dd, 4H, J ) 7.8,
1.0 Hz); 6.10-5.98 (m, 2H); 5.39 (dt, 2H, J ) 17.4, 1.2 Hz); 5.26
(dt, 2H, J ) 10.8, 1.2 Hz); 4.49 (d, 4H, J ) 4.5 Hz); 1.62 (s, 6H).
2,2-Bis[3′-a llyl-4′-h yd r oxyp h en yl]p r op a n e (5). The crude
compound 4b (31 g, 0.10 mol) was heated to 160-180 °C for 4 h
under argon and then cooled to ambient temperature to give a
brown oil (30 g, 95%). 1H NMR (CDCl3): δ 6.95 (d, 2H, J ) 7.8
Hz); 6.94 (s, 2H); 6.69 (d, 2H, J ) 7.8 Hz); 5.98 (m, 2H); 5.11
(dt, 4H, J ) 9.9, 1.2 Hz); 4.82 (bs, 2H, OH); 3.25 (d, 4H, J ) 6.3
Hz); 1.59 (s, 6H).
2,2-Bis[3′-pr opyl-4′-h ydr oxyph en yl]pr opan e (6). The crude
compound 5 (62 g, 0.20 mol) was dissolved in methanol (1 L),
and to this solution was added 5% Pd/C (5 g). The solution was
degassed by purging with argon, and then hydrogen gas was
bubbled through the solution for 24 h. The solution was filtered
through Celite to remove the Pd/C, and the solvent was
evaporated under reduced pressure to give an orange oil (60 g,
98%). 1H NMR (CDCl3): δ 6.93 (s, 2H); 6.91 (d, 2H, J ) 7.6
Hz); 6.63 (d, 2H, J ) 7.6 Hz); 4.58 (s, 2H); 2.51 (t, 4H, J ) 7.6
Hz); 1.59 (s, 6H); 1.55 (m, 2H); 0.91 (t, 6H, J ) 7.3 Hz).
2,2,14,14-Tetr a m eth yl-8,11,17,23-tetr a p r op yl-6,10,18,22-
tetr a h yd r oxyca lix[4]a r en e (7). The crude compound 6 (3.12
g, 10 mmol) and paraformaldehyde (0.38 g, 12 mmol) were
dissolved in dried methylene chloride (1 L). The solution was
degassed by purging with argon, and then BF3‚OEt2 (1.30 mL,
10 mmol) was added by syringe. The solution turned green after
several minutes, and it was stirred at ambient temperature for
12 h. Water (200 mL) was added to quench the reaction and
the methylene chloride solution was washed with two 200 mL
portions of water and two 200 mL portions of brine and dried
over Mg2SO4. The solvent was then evaporated under reduced
pressure to give a yellow solid. The product was purified by
chromatography on silica gel column using hexane-ethyl acetate
(4:1). The second component was collected by combining ap-
propriate fractions, and the solvent was evaporated under
reduced pressure. The residue was crystallized from CHCl3-
hexanes to yield a white solid (712 mg, 22%). Mp: 213 °C. 1H
NMR (CDCl3): δ 7.02 (d, 4H, J ) 2.4 Hz); 6.62 (d, 4H, J ) 2.4
Hz); 5.82 (s, 4H); 3.71 (s, 4H); 2.53 (t, 8H, J ) 7.8 Hz); 1.67-
1.55 (m, 20H); 0.96 (t, 12H, J ) 7.5 Hz). MS {EI} m/ e: calcd
648.42, found 648.42. Anal. Calcd for C44H56O4‚H2O: C, 79.3;
H, 8.77. Found: C, 79.4, H, 8.70.
Syn th esis of Cova len tly-Lin k ed
exo-Ca lix[4]a r en es
Thomas N. Sorrell* and Hongping Yuan
Department of Chemistry, The University of North Carolina
at Chapel Hill, Chapel Hill, North Carolina 27599-3290
Received September 24, 1996
Calix[4]arenes, or endo-calix[4]arenes, 1 have been
extensively studied for the past several decades,1 but exo-
calix[4]arenes 2 have only recently attracted much
attention.2-4 With respect to structure, an exo-calixarene,
having the OH groups on the “upper rim” of the bowl-
shaped molecules, is actually more similar to a resor-
cinarene (3a )5 or cavitand (3b)5 than to the corresponding
endo-isomer. We report here the preparation of a tetra-
(propyl-substituted) exo-calix[4]arene and a study of the
conformational properties of it and some covalently-
linked derivatives.
Mon o- a n d Bis(m eth ylen e-lin k ed )-2,2,14,14-tetr a m eth yl-
8,11,17,23-t e t r a p r op yl-6,10,18,22-t e t r a h yd r oxyca lix[4]-
a r en e (8a a n d 9a ). A solution of calixarene 7 (312 mg, 0.500
mmol) and K2CO3 (690 mg, 5.00 mmol) in 200 mL of DMF was
degassed by purging with argon; CH2BrCl (0.66 mL, 1.20 mmol)
was then added. The solution was heated at reflux for 48 h
under argon. After that, the solution was filtered; and the DMF
was evaporated under reduced pressure. The residue was
dissolved in ethyl acetate, and this solution was washed with
two 100 mL portions of dilute hydrochloric acid, two 100 mL
portions of brine and dried over MgSO4. Evaporation of the
solvent gave a yellow solid, which was purified by chromatog-
raphy on silica gel column using hexane-ethyl acetate (9:1). The
first component was collected, and the solvent was evaporated
under reduced pressure. The residue was crystallized from
CHCl3-hexanes to yield a white solid, 9a (25 mg, 15%). Mp:
>300 °C. 1H NMR (CDCl3): δ 7.13 (d, 4H, J ) 2.1 Hz); 6.66 (d,
4H, J ) 2.1 Hz); 6.02 (d, 2H, J ) 7.2 Hz); 4.65 (d, 2H, J ) 7.2
Hz); 4.45 (d, 2H, J ) 12 Hz); 3.05 (d, 2H, J ) 12 Hz); 2.61-2.50
(m, 8H); 1.68-1.50 (m, 20H); 0.97 (t, 12H, J ) 7.5 Hz). Anal.
Calcd for C46H56O4‚H2O: C, 80.1; H, 8.47. Found: C, 80.0; H,
8.38. MS {EI} m/ e: calcd 672.42, found 672.42.
Exp er im en ta l Section
Gen er a l. All reagents used were analytical grade. DMF,
CH2Cl2, and CHCl3 were distilled from CaH2. 1H NMR spectra
were recorded on a Varian VXR 300 MHz or on a Varian XL400
spectrometer. Mass spectra and high-resolution mass spectra
were obtained at the Mass Spectrometry Laboratory for Bio-
technology at the North Carolina State University in Raleigh.
Elemental analyses were performed by Atlantic Microlabs,
Norcross, GA.
2,2-Bis[4′-(a llyloxy)p h en yl]p r op a n e (4b). Bisphenol A
(235 g, 1.00 mol), allyl chloride (330 mL, 4.00 mol), potassium
(1) For recent reviews see: (a) Gutsche, C. D. in Calixarenes,
Monograph in Supramolecular Chemistry; Stoddart, J . F., Ed.; Royal
Society of Chemistry: Cambridge, 1989; Vol. 1. (b) Calixarenes:
Versatile Class of Macrocyclic Compounds; Vicens, J ., Bohmer, V., Eds.;
Kluwer Academic: Dordrecht, The Netherlands, 1991.
(2) Chasar, D. W. J . Org. Chem. 1985, 50, 545-546.
A
(3) (a) Bohmer, V.; Dorrenbacher, R.; Frings, M.; Heydenreich, M.;
de Paoli, D.; Vogt, W.; Ferguson, G.; Thondorf, I., J . Org. Chem. 1996,
61, 549-559. (b) Thondorf, I.; Brenn, J .; Brandt, W.; Bohmer, V.
Tetrahedron Lett. 1995, 36, 6665-6668. (c) Bohmer, V.; Dorrenbacher,
R.; Vogt, W.; Zetta, L. Tetrahedron Lett. 1992, 33, 769-772.
(4) (a) G. Sartori, G.; Bigi, F.; Porta, C.; Maggi, R.; Mora, R.
Tetrahedron Lett. 1995, 36, 2311-2314. (b) Sartori, G..; Maggi, R; Bigi,
F.; Arduini, A.; Pastorio, A.; Porta, C. J . Chem. Soc., Perkin Trans. 1
1994, 13, 1657-1658.
The second component was also collected, and the solvent was
evaporated under reduced pressure. The residue was crystal-
lized from CHCl3-hexanes to yield a white solid, 8a (135 mg,
41%). Mp: 203 °C. 1H NMR (CDCl3): δ 7.11 (d, 2H, J ) 2.7
Hz); 7.03 (d, 2H, J ) 2.7 Hz); 6.77 (d, 2H, J ) 2.7 Hz); 6.48 (d,
2H, J ) 2.7 Hz); 6.01 (s, 2H), 5.98 (d, 1H, J ) 6.8 Hz); 4.57 (d,
1H, J ) 6.8 Hz); 4.51 (d, 1H, J ) 12 Hz); 4.08 (d, 1H, J ) 14.7
(5) Bohmer, V. Angew. Chem., Int. Ed. Engl. 1995, 34, 713-745.
S0022-3263(96)01815-4 CCC: $14.00 © 1997 American Chemical Society