P. Rajakumar, M. Srisailas / Tetrahedron 59 (2003) 5373–5376
5375
dried over anhydrous sodium sulfate. Column chromato-
graphy was carried out with silica gel (ACME, 100–200
mesh). m-Terphenyl dibromide was synthesized following
the literature procedure.6a
70.7, 110.9, 115.5, 120.5, 123.7, 124.8, 124.9, 125.3, 125.5,
125.8, 126.7, 126.8, 127.1, 127.4, 128.1, 128.4, 129.3,
130.8, 133.4, 134.3, 136.6, 140.5, 153.7; m/z (FAB-MS) 752
(Mþ). Anal. Calcd for C54H40O4: C, 86.14; H, 5.36. Found:
C, 86.09; H, 5.38.
3.1.1. Dialdehyde 2. To a solution of m-terphenyl
dibromide (4.16 g, 10 mmol) in DMF was added p-hydroxy-
benzaldehyde (2.564 g, 21 mmol) and anhydrous K2CO3
(14.0 g) and the reaction mixture was stirred at 608C for
48 h. Then, the reaction mixture was added to a large
amount of water (1 L) and digested over a water bath for
30 min. The residue obtained was extracted with CHCl3
(4£100 mL) and the extracts were washed with water
(3£100 mL); with brine (200 mL) and dried. Evaporation of
the organic layer gave the dialdehyde 2, which was purified
over silica gel using hexane/CHCl3 (1:1). Colourless solid;
yield 77%; mp 2058C; IR (KBr, cm21) 3050, 1682 (CvO),
3.1.5. Diester 6a. m-Terphenyl dibromide (4.16 g,
10 mmol) and methyl m-hydroxycinnamate (3.76 g,
21 mmol) in dry DMF (40 mL) was treated with anhydrous
K2CO3 (14 g) at 608C for 48 h. Then, the reaction mixture
was worked up as described for dialdehyde 4. The crude
product was purified over silica using hexane/CHCl3 (1:2)
to afford the diester 6a as a colourless solid. Yield 56%; mp
192–1948C; IR (KBr, cm21) 3050, 1704 (CvO), 1600; 1H
NMR d 3.79 (s, 6H); 5.12 (s, 4H); 6.42 (d, 2H, J¼16.1 Hz);
7.02 (d, 2H, J¼4 Hz); 7.13 (d, 4H, J¼4 Hz); 7.23 (s, 1H);
7.30 (t, 2H, J¼4 Hz); 7.52 (d, 4H, J¼7.8 Hz); 7.58 (d, 2H,
J¼6.8 Hz); 7.63 (s, 1H); 7.66 (d, 4H, J¼7.8 Hz); 7.80 (s,
2H); 13C NMR d 51.7, 69.7, 114.0, 116.9, 118.1, 121.0,
125.9, 126.2, 127.5, 127.9, 129.2, 129.9, 135.8, 140.9,
141.3, 144.7, 158.9, 167.3, 196.4; m/z (EI, 70 eV) 610 (Mþ,
6), 562 (15), 537 (14), 471 (20), 467 (100), 386 (11), 366
(70), 271 (56), 257 (72), 236 (36), 184 (74), 149 (84), 158
(46). Anal. Calcd for C40H34O6: C, 78.67; H, 5.61. Found:
C, 78.62; H, 5.58.
1
1605; H NMR (400 MHz, CDCl3) d 5.18 (s, 4H); 7.09 (d,
4H, J¼8.8 Hz); 7.52 (d, 4H, J¼8.3 Hz); 7.57 (d, 2H,
J¼4 Hz); 7.59 (t, 1H, J¼4 Hz); 7.67 (d, 4H, J¼8.3 Hz);
7.79 (s, 1H); 7.84 (d, 4H, J¼8.8 Hz); 9.88 (s, 2H); 13C NMR
(100.4 MHz, CDCl3) d 69.9, 115.1, 125.9, 126.3, 127.5,
128.0, 129.3, 130.1, 131.9, 135.1, 141.1, 141.2, 163.6,
190.7; m/z (EI, 70 eV) 498 (Mþ, 5), 369 (17), 302 (5), 271
(100), 200 (9), 165 (17), 87 (27). Anal. Calcd for
C34H26O4:C, 81.91; H, 5.26. Found: C, 81.85; H, 5.27.
3.1.6. Diester 6b. m-Terphenyl dibromide (4.16 g,
0.01 mol) and methyl p-hydroxycinnamate (3.76 g,
0.021 mol) was treated as described above. The crude
product was chromatographed over silica using hexane/
CHCl3 (1:2) to afford the diester 6b as a colourless solid.
Yield 43%; mp 1778C; IR (KBr, cm21) 3050, 1690 (CvO),
3.1.2. Diol 3. To a solution of the dialdehyde 2 (3.984 g,
8 mmol) in methanol (70 mL) was added in portions NaBH4
(0.151 g, 4 mmol) at 08C. The reaction mixture was stirred
at rt for 6 h, after which conc. HCl (10 drops) was added.
The residue obtained was filtered off. Evaporation of the
solvent in vacuo gave the diol 3, which was recrystallized
from CHCl3/MeOH (5:1). Yield 95%; mp 2088C (lit.6b
2088C).
1
1600; H NMR d 3.52 (s, 6H); 5.07 (s, 4H); 6.24 (d, 2H,
J¼15.6 Hz); 6.72–6.93 (m, 4H), 7.17–7.92 (m, 18H); 13C
NMR d 59.6, 69.8, 115.2, 117.5, 126.3, 127.1, 127.5, 127.9,
128.3, 128.9, 129.3, 130.3, 135.6, 141.3, 144.4, 160.5,
193.3. m/z (EI, 70 eV) 610 (Mþ, 8), 562 (12), 551 (7), 525
(24), 492 (41), 386 (17), 288 (62), 243 (24), 184 (76), 153
(36). Anal. Calcd for C40H34O6/C, 78.67; H, 5.61. Found: C,
78.63; H, 5.59.
3.1.3. Dibromide 4. To a stirred suspension of diol 4
(3.012 g, 6 mmol) in CH2Cl2 (120 mL), PBr3 (0.3 mL,
3 mmol) was added and the reaction mixture was stirred at
08C for 12 h. The reaction was poured into water (500 mL)
and the organic layer was washed with water (3£150 mL);
with brine (200 mL) and dried. The solvent was evaporated
in vacuo to give dibromide 4, which was recrystallized from
hexane/CH2Cl2 (1:5). Colourless solid; yield 92%; mp
3.1.7. Diol 7a. To a solution of diester 6a (8.418 g,
13.8 mmol) in dry THF (300 mL) was added in portions
lithium aluminium hydride (0.656 g, 17.3 mmol) at 08C.
The reaction mixture was stirred at rt for 6 h and then run
into Na2SO4.10H2O (20 g) and stirred. The mixture was
then digested on a steam bath (20 min) and filtered. The
inorganic residue was further extracted (Soxhlet) with THF
(200 mL). The combined THF fractions, on evaporation,
gave the corresponding alcohol, which was purified by
recrystallization from a minimum volume of THF/MeOH
(4:1). Colourless solid; yield 51%; mp 2128C; IR
1
1428C; IR (KBr, cm21) 3050, 1605; H NMR (400 MHz,
CDCl3) d 4.57 (s, 4H); 5.01 (s, 4H); 6.70–6.81 (m, 4H);
7.02–7.48 (m, 16H); m/z (FAB-MS) 632 (Mþþ 4); 630
(Mþþ2); 628 (Mþ). Anal. Calcd for C34H28O2Br2: C,
64.99; H, 4.49. Found: C, 65.12; H, 4.62.
3.1.4. Cyclophane 5. Dibromide 4 (0.314 g, 0.5 mmol) and
(S)-BINOL (0.143 g, 0.5 mmol) were stirred with K2CO3
(20 mmol) in acetone (400 mL) at room temperature for
120 h, after which the reaction mixture was acidified and
evaporated to dryness. The residue obtained was extracted
with CH2Cl2 (3£100 mL), washed with 10% NaOH
(2£50 mL); with water (3£100 mL) and dried (MgSO4).
Evaporation of the organic layer gave a residue, which was
chromatographed over SiO2 using hexane/CHCl3 (1:1) to
afford the chiral cyclophane 5 as a colourless solid. Yield
38%; mp 1788C; [a]2D5¼-186 (c 0.4, CHCl3); IR
1
(KBr, cm21) 3300, 3050, 1626, 1600; H NMR (DMSO-
d6) d 5.08 (s, 4H); 5.37–5.41 (m, 4H); 6.72 (bs, 2H,
exchangeable with D2O); 6.92–8.01 (m, 24H); m/z (EI,
70 eV) 554 (Mþ, 11), 499 (6), 478 (14), 445 (4), 413 (23),
384 (62), 308 (18), 288 (41), 229 (100), 184 (36), 153 (42).
Anal. Calcd For C38H34O4: C, 82.28; H, 6.18. Found: C,
82.14; H, 6.07.
3.1.8. Diol 7b. Following the procedure as above, the
treatment of diester 6b with lithium aluminium
hydride gave the diol 7b as a colourless solid. Yield 57%;
1
(KBr, cm21) 3050, 1605; H NMR d 4.90–5.90 (m, 8H);
6.86–7.38 (m, 20H); 7.77–7.87 (m, 12H); 13C NMR d 70.1,