1034
J. Kobayashi and T. Kawashima
bipyramidal structure in spite of its thermodynamically disfavored ar-
rangement around the central phosphorus atom.
EXPERIMENTAL
4b: To a solution of 1 (35.4 mg, 72.5 µmol) in THF (5 mL), a solution of t-
BuLi in pentane (1.77 M, 0.22 mmol) at −78◦C was added. After stirring
for 1 h at −78◦C, the mixture was treated with H2O and extracted
with CHCl3. The extracts were dried over anhydrous MgSO4. After
removal of the solvent, 2b (37.1 mg) was obtained as a colorless oil. To
a solution of 2b in CDCl3 (0.5 mL), iodine (10.3 mg, 40.6 µmol) was
added in the presence of Et3N (0.05 mL). The mixture was stirred for
30 min at ambient temperature and treated with a Na2SO3 solution
and extracted with CHCl3. The extracts were dried over anhydrous
MgSO4. After removal of the solvent, the crude reaction products were
separated by HPLC to give 4b (23.5 mg, 60%). 4b: colorless crystals; mp
187–190◦C.1H NMR (500 MHz, CDCl3, TMS, 27◦C): δ = 1.32 (s, 27H),
1.43 (d, JPH = 19.2 Hz, 9H), 6.91 (d, J = 8.4 Hz, 3H), 7.12 (dd, J = 8.4,
1
2.1 Hz, 3H), 7.87 (br s, 3H). 13C{ H} NMR (125 MHz, CDCl3, 27◦C):
δ = 29.2 (d, JPC = 4.4 Hz), 31.6 (s), 34.4 (s), 40.3 (d, JPC = 136.9 Hz),
42.2 (d, JPC = 207.5 Hz), 111.9 (d, JPC = 8.8 Hz), 122.0 (d, JPC = 22.0
Hz), 124.2 (d, JPC = 11.6 Hz), 132.6 (d, JPC = 11.2 Hz), 145.6 (s), 149.8
(d, JPC = 2.9 Hz). 31P NMR (109 MHz, CDCl3, 27◦C): δ = 22. HRMS (EI
70 eV): m/z 502.2637, Calcd for C32H39O3P 502.2606.
4a, 4c, and 4d were prepared by a similar procedure.
4a: colorless solid. 1H NMR (500 MHz, CDCl3, TMS, 27◦C): δ = 1.00
(t, J = 7.4 Hz, 3H), 1.32 (s, 27H), 1.48–1.51 (m, 2H), 1.83–1.85 (m, 2H),
2.00–2.06 (m, 2H), 6.90 (d, J = 8.5 Hz, 3H), 7.12 (dd, J = 8.5, 2.1 Hz,
1
3H), 7.87 (br s, 3H). 13C{ H} NMR (125 MHz, CDCl3, 27◦C): δ = 14.0
(s), 24.5 (d, JPC = 24.8 Hz), 28.2 (d, JPC = 7.9 Hz), 31.5 (s), 34.4 (s), 35.9
(d, JPC = 207.3 Hz), 40.2 (d, JPC = 134.5 Hz), 111.9 (d, JPC = 9.5 Hz),
122.0 (d, JPC = 22.3 Hz), 124.0 (s), 132.5 (d, JPC = 12.0 Hz), 145.7 (s),
149.6 (d, JPC = 3.7 Hz). 31P NMR (109 MHz, CDCl3, 27◦C): δ 22.
1
4d: colorless solid. H NMR (500 MHz, toluene-d8, TMS, 27◦C): δ =
1.28 (s, 27H), 2.16 (s, 3H), 2.65 (d, JPH = 1.4 Hz, 6H), 6.78 (d, J = 8.4
Hz, 3H), 6.82 (d, JPH = 6.4 Hz, 2H), 6.90 (dd, J = 8.4, 2.1 Hz, 3H), 8.19
1
(br s, 3H). 13C{ H} NMR (125 MHz, toluene-d8, 27◦C): δ = 20.7 (s), 25.8
(d, JPC = 4.4 Hz), 31.5 (s), 34.4 (s), 46.0 (d, JPC = 123.8 Hz), 112.8 (d,
JPC = 9.5 Hz), 121.8 (d, JPC = 22.0 Hz), 124.5 (s), 130.1 (d, JPC = 19.9
Hz), 132.6 (d, JPC = 12.5 Hz), 137.1 (s), 137.9 (d, JPC = 11.0 Hz), 141.9
(d, JPC = 248.0 Hz), 145.5 (s), 151.0 (d, JPC = 4.8 Hz). 31P NMR (109
MHz, toluene-d8, 27◦C): δ = 29.