graphy (1:1 acetone–light petroleum) to give the silylated
phenol (8.56 g, 97%) as a viscous oil; νmax(film) 2932, 2858,
1702, 1583, 1482, 1278, 833, 742, 701 cmϪ1. Found: Mϩ
360.1544. C23H24O2Si requires 360.1545.
and dry THF (30 cm3) under argon at Ϫ78 ЊC was added a
solution of n-butyllithium (1.6 mol dmϪ3, 4.6 cm3, in hexane)
and stirring continued for 45 min. A solution of the alcohol 26
(1.9 g, 3.6 mmol) in dry THF (10 cm3) was slowly added and
stirring continued for a further 45 min. Adamantan-2-one (0.59
g, 3.93 mmol) in dry THF (120 cm3) was added, the solution
allowed to warm to room temperature and stirring continued
for a further 3 h. Toluene-4-sulfonyl chloride (0.69 g, 3.6 mmol,
1.0 equiv.) in dry THF (10 cm3) was added and the mixture
stirred for a further 16 h. The reaction mixture was then poured
into an excess of 0.1 mol dmϪ3 phosphate buffer at pH 7.0 and
the product extracted into ether (2 × 100 cm3). The ether
extract was washed with brine before drying, filtering and evap-
oration under reduced pressure to give a viscous oil. This was
purified by chromatography (1:10 acetonitrile–light petroleum)
to afford the title compound as a white powdery solid (0.50 g,
20%), mp 95–97 ЊC; νmax(CHCl3 film) 2924, 2853, 1597, 1360,
1283, 1257, 1113, 1097, 819, 737, 707 cmϪ1; δH 1.09 [9 H, s,
(CH3)3C], 1.37–1.86 (12 H, m, adamantanyl-H), 2.33 (1 H,
br s, adamantanyl-H), 2.44 (3 H, s, CH3Ar), 3.02 (1 H, s,
adamantanyl-H), 3.26 (2 H, t, J 4 Hz, CH2), 3.91 (2 H, t, J 4 Hz,
CH2), 6.52 (1 H, s, ArH), 6.75 (1 H, d, J 8 Hz, ArH), 6.77 (1 H,
d, J 8 Hz, ArH), 7.07 (1 H, t, J 8 Hz), 7.30–7.39 (6 H, m, ArH),
7.40 (2 H, m, ArH), 7.69 (4 H, m, ArH), 7.76 (2 H, m, ArH);
m/z (EI) 693 (Mϩ), 522. Found: C, 73.1; H, 7.2. C42H48O5SSi
requires C, 72.8; H, 7.0%.
A solution of the protected aldehyde (3.61 g, 10 mmol),
ethylene glycol (1.5 cm3, 2.7 equiv.) and a few crystals of dried
toluene-4-sulfonic acid in toluene (30 cm3) was heated to a
gentle reflux, using a Dean–Stark apparatus to azeotrope off
the water formed. After 2.5 h the solution was neutralised with
a saturated aqueous sodium hydrogen carbonate solution, and
the organic phase then washed with brine (2 × 30 cm3), dried,
filtered and the solvent removed under reduced pressure. The
product pale orange oil was distilled to afford the title acetal
(3.60 g, 89%) as a pale yellow oil, bp 244–246 ЊC/2 Torr;
νmax(film) 2932, 2859, 1589, 1486, 1283, 1113, 822, 742, 701
cmϪ1; δH 1.11 [9 H, s, (CH3)3C], 4.00 (4 H, m, 2 × CH2), 5.76
(1 H, s, ArCH), 6.76 (1 H, d, J 8 Hz, ArH), 6.98 (1 H, s, ArH),
6.99 (1 H, d, J 8 Hz, ArH), 7.05 (1 H, dd, J 7, 8 Hz), 7.34–7.42
(6 H, m, ArH), 7.70–7.74 (4 H, m, ArH); m/z (EI) 404 (Mϩ), 347
(Mϩ Ϫ C4H9), 303. Found Mϩ 404.1794. C25H28O3Si requires
404.1808.
Dimethyl 1-(3-tert-butyldiphenylsilyloxyphenyl)-1-(2-hydroxy-
ethoxy)methylphosphonate 26
To a solution of the ethylene acetal 25 (2.25 g, 5.6 mmol) in
dichloromethane (40 cm3), under argon at Ϫ78 ЊC, was added,
dropwise, titanium() chloride (1 cm3, 9.1 mmol). To the
stirred solution was added trimethyl phosphite (1 cm3, 8.5
mmol) and the solution stirred at Ϫ78 ЊC for a further 30 min
prior to warming to room temperature and stirring for a further
45 min. The reaction was quenched by pouring into an excess of
saturated aqueous sodium hydrogen carbonate solution and
then extraction into ethyl acetate (4 × 50 cm3). The organic
extract was washed with brine, dried, filtered and evaporated
under reduced pressure to afford a light brown oil. The crude
product was purified by chromatography (2:1 acetone–light
petroleum) to afford the title compound as a colourless oil (1.95
g, 68%); νmax(film) 3408, 2956, 2858, 1600, 1483, 1277, 1113,
1038, 822, 742, 701 cmϪ1; δH 1.09 [9 H, s, (CH3)3C], 2.70 (1 H, br
s, D2O exch., OH), 3.46 (2 H, t, J 4 Hz, CH2O), 3.47, 3.49 (6 H,
d, J 10 Hz, CH3O), 3.61 (2 H, t, J 4 Hz, CH2O), 4.53 (1 H, d,
J 16 Hz, ArCH), 6.78 (1 H, d, J 8 Hz, ArH), 6.80 (1 H, s, ArH),
6.92 (1 H, d, J 8 Hz, ArH), 7.11 (1 H, t, J 8 Hz, ArH), 7.34–7.42
(6 H, m, ArH), 7.70–7.74 (4 H, m, ArH); m/z (EI) 514 (Mϩ),
457, 426. Found: Mϩ 514.1930. C27H35O6PSi requires 514.1941.
Dimethyl 1-(3-tert-butyldiphenylsilyloxyphenyl)-1-(2-amino-
ethoxy)methylphosphonate 30
To a solution of the phthalimide 29 (1.0 g, 1.7 mmol) in ethanol
(10 cm3) was added hydrazine hydrate (0.9 cm3, 2.55 mmol, 1.5
equiv.). The mixture was stirred at 50 ЊC until the solution
became turbid, after about 15 min. The slurry was poured into
an excess of 2 M aqueous hydrochloric acid (20 cm3) and the
mixture heated at 100 ЊC on a steam bath for 10 min. The mix-
ture was cooled and the solid phthalohydrazide that formed
was removed by filtration. The filtrate was basified to pH 8,
with the addition of 2 M aqueous sodium carbonate solution
before extraction with ethyl acetate (2 × 25 cm3), washing with
brine, drying, filtering and evaporation to afford the title com-
pound as a viscous pale yellow oil (0.523 g, 60%); νmax(film)
3251, 2956, 2858, 1659, 1600, 1277, 1113, 1055, 822, 743, 703
cmϪ1; δH 1.09 [9 H, s, (CH3)3C], 2.44 (2 H, br s, exch. D2O,
NH2), 3.41–3.56 (8 H, m, CH2 and CH3O), 4.20 (2 H, t, J 4 Hz,
CH2), 4.47 (1 H, d, J 16 Hz, CHP), 6.67 (2 H, m, ArH), 6.92
(1 H, d, J 8 Hz, ArH), 7.1 (1 H, m, ArH), 7.32–7.43 (6 H, m,
ArH), 7.65–7.72 (4 H, m, ArH); m/z (CI) 531 (MNH4ϩ), 514
(MHϩ), 483, 456, 404. Found: Mϩ 531.6821. C27H36NO5PSiؒ
NH4ϩ requires 531.6827.
Dimethyl 1-(3-tert-butyldiphenylsilyloxyphenyl)-1-(2-phthal-
imidoethoxy)methylphosphonate 29
A solution of the alcohol 26 (3.31 g, 6.5 mmol), triphenyl-
phosphine (1.85 g, 7.1 mmol) and phthalimide (0.96 g, 6.5
mmol) in dry THF (35 cm3) was cooled to 0 ЊC and diethyl
azodicarboxylate (1.1 cm3) added dropwise over 10 min. The
mixture was stirred for a further 10 min before allowing to
warm to room temperature for 1.5 h. The solvent was removed
under reduced pressure and the crude oil obtained was chrom-
atographed, using 2:1 ethyl acetate–light petroleum as eluant,
to afford the title compound as a pale viscous oil (2.67 g, 70%);
νmax (CHCl3 film) 2955, 2858, 1774, 1712, 1601, 1277, 1112,
1036, 823, 763, 722 cmϪ1; δH 1.00 [9 H, s, (CH3)3C], 3.46 and
3.48 (6 H, d, J 10 Hz, 2 × CH3O), 3.54 (2 H, t, J 4 Hz, CH2),
3.75 (2 H, t, J 4 Hz, CH2), 4.49 (1 H, d, J 15 Hz, CHP), 6.70
(1 H, d, J 8 Hz, ArH), 6.80 (1 H, s, ArH), 6.83 (1 H, d, J 8 Hz,
ArH), 6.85 (1 H, dd, J 1, 8 Hz, ArH), 7.34–7.36 (6 H, m, ArH),
7.71 (6 H, m, ArH), 7.82 (2 H, m, ArH); m/z (CI) 644 (MHϩ),
535, 454. Found: 643.7475. C35H38NO7PSi requires 643.7470.
4Ј-Methoxy-4Ј-phenylspiro[adamantane-2,3Ј-[1,2]dioxetane] 33
A solution of the vinyl ether 17 (0.30 g, 1.2 mmol) and Methyl-
ene Blue (1 mg) in dichloromethane, kept at room temperature,
was irradiated with a water-cooled 400 W medium pressure Hg
arc lamp whilst oxygen was bubbled through the solution. After
40 min, when no starting material remained, irradiation was
stopped and the solution was passed through a plug of silica gel
to remove the sensitizer, washing with more dichloromethane.
Removal of solvent under reduced pressure afforded the title
peroxide as a crystalline solid (0.32 g, 93%), mp 85–88 ЊC
(lit.22 84–85 ЊC); δH 1.55–2.10 (12 H, m, adamantanyl-H), 2.17
(1 H, s, adamantanyl-H), 3.05 (1 H, s, adamantanyl-H), 3.22
(3 H, s, CH3O), 7.42–7.46 (5 H, m, ArH).
4Ј-Methoxy-4Ј-(3-hydroxyphenyl)spiro[adamantane-2,3Ј-[1,2]-
dioxetane] 34
1-(2-Adamantylidene)-1-[2-(4-tolylsulfonyloxy)ethoxy]-1-(3-
tert-butyldiphenylsilyloxyphenyl)methane 28
To a solution of diisopropylamine (2 cm3, 14.3 mmol, 3 equiv.)
Prepared in a similar manner to compound 33, but from the
phenol 19 (0.214 g, 0.8 mmol). The product peroxide (0.22 g,
90%) showed mp 129–133 ЊC (decomp.) (lit.5 135 ЊC); δH 1.54–
J. Chem. Soc., Perkin Trans. 1, 2000, 2243–2248
2247