General Papers
ARKIVOC 2013 (iii) 98-108
65.2, 94.2, 103.50, 115.9, 127.8, 131.2, 157.9. HRMS (FAB) calcd. for [M+H+] (C11H15O4),
211.0970; found 211.0970.
2-(4-(Benzyloxy) phenyl)-1,3-dioxolane (19a). A mixture of 4-(benzyloxy)benzaldehyde (0.5 g,
2.36 mmol), ethylene glycol (0.9 g, 14.13 mmol) and p-TsOH.H2O (36 mg, 0.19 mmol) in dry
benzene (15 mL) was equipped with a Dean-Stark apparatus and heated to reflux for 24h. After
cooling the mixture to room temperature, added 10 mL of saturated aq. Sodium bicarbonate
solution and extracted with ethyl acetate (2 × 25 mL) combined organic layers were washed with
brine (20 mL), dried over sodium sulfate. Solvent was removed under reduced pressure and the
residue was purified by silica gel column chromatography (20%, ethyl acetate: hexanes, trace
amount of triethylamine) to give the title compound (0.40 g, 1.57 mmol, 67%) as a colorless oil.
1H NMR (300 MHz, CDCl3) 3.97-4.13 (m, 4H), 5.06 (s, 2H), 5.74 (s, 1H) 6.94-6.98 (m, 2H),
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7.29-7.42 (m, 7H); C NMR (75 MHz, CDCl3) 65.2, 70.0, 103.6, 115.2, 117.7, 127.4, 127.8,
127.9, 128.5, 136.8, 159.5.34
2-(4-(4-(1,3-Dioxolan-2-yl)butoxy)phenyl)-1,3-dioxolane (20a). A suspension of 4-(5-
oxopentyloxy)benzaldehyde (0.5 g, 2.42 mmol), ethylene glycol (0.9 g, 14.54 mmol) and p-
TsOH·H2O (37 mg, 0.19 mmol) in dry toluene (15 mL) was equipped with a Dean-Stark
apparatus and heated to reflux for 12h. After cooling the mixture to room temperature, added 10
mL of saturated aq. sodium bicarbonate solution and extracted with ethyl acetate (2 × 20 mL),
combined organic layers were washed with brine (20 mL), dried over sodium sulfate. Solvent
was removed under reduced pressure and the residue was purified by silica gel column
chromatography (20%. ethyl acetate: hexanes, trace amount of triethylamine) to give the title
1
compound (0.506 mg, 1.72 mmol, 73%) as a colorless oil. H NMR (300 MHz, CDCl3) 1.67-
1.82 (m, 6H), 3.81-4.09 (m, 10H), 4.85 (t, 9 Hz, 3H), 5.71 (s, 1H), 6.85 (d, 8.7 Hz, 2H), 7.35 (d,
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4.35 Hz, 2H); C NMR (75 MHz, CDCl3) 20.5, 29.0, 33.4, 64.8, 65.2, 67.7, 103.7, 104.3,
114.2, 127.8, 129.7, 159.8. HRMS (FAB) calcd. for [M+H+] (C16H23O5), 295.1546; found
295.1538.
4-(4-(1,3-Dioxolan-2-yl)butoxy)benzaldehyde (20b). The standard procedure for the
deprotection was followed. Starting with 20a (100.1 mg, 0.34 mmol), 20b was isolated after
silica gel column chromatography (20% Ethyl acetate: Hexane, trace amount of triethylamine),
as a colorless oil, (61.2 mg, 0.24 mmol, 72%). 1H NMR (300 MHz, CDCl3) 1.72-1.89 (m, 6H),
3.81-4.05 (m, 6H), 4.86 (t, 4.8 Hz, 3H), 6.95 (d, 8.7 Hz, 2H), 7.79 (d, 8.7 Hz, 2H), 9.85 (s, 1H);
13C NMR (75 MHz, CDCl3), 20.5, 28.9, 33.4, 64.9, 68.1, 104.3, 114.7, 129.7, 132, 164.1, 190.8.
HRMS (EI) calcd. for [M+] (C14H18O4) 250.1205, found 250.1206.
2,4-Diphenyl-1,3-dioxolane (22). To a solution of 1-phenylethane-1,2-diol (500 mg, 3.62 mmol)
and benzaldehyde (576 mg, 5.42 mmol) in dry dichloromethane (6 mL) was added p-TsOH·H2O
(63 mg, 0.09 mmol). The reaction mixture was stirred at room temperature for 15 h, then diluted
with 10 mL dichloromethane and washed with 5 mL of saturated aqueous sodium bicarbonate
solution, washed with 5 mL of brine solution. The organic layer was dried over sodium sulfate
and the solvents were removed under reduced pressure. The residue was purified by flash
column chromatography (2%, ethylacetate: hexanes with trace amount of triethylamine) to give
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