Y. Wang et al. / Tetrahedron 58 (2002) 7101–7107
7105
1.1.5.
3-Methyl-4-oxo-3-phenylpentanenitrile
(7d).
95:5) afforded 7g (0.094 g, 80%) as a colorless oil: IR (film)
1
Sodium cyanide (0.12 g, 2.4 mmol) was dissolved in
distilled water (0.20 mL). A solution of 3-methyl-2-
methylene-3-phenyloxetane (1) (0.07 g, 0.4 mmol) in
DMF (0.80 mL) was added. The mixture was stirred for
3 h at 1008C, then cooled to rt. Water (6 mL) was added, and
the mixture was extracted with Et2O (3£6 mL). The
combined organic extracts were dried (Na2SO4) and
concentrated in vacuo. Purification by flash chromatography
on silica gel (petroleum ether/EtOAc 90:10) afforded 7d
(0.043 g, 53%) as a colorless oil: IR (film) 2245, 1709,
1707, 1507, 1227, 1042, 824 cm21; H NMR (400 MHz,
CDCl3) d 7.38–7.24 (m, 5H), 6.80 (m, 4H); 4.46 (d, J¼
8.9 Hz, 1H), 4.15 (d, J¼8.9 Hz, 1H), 3.74 (s, 3H), 2.02 (s,
3H), 1.69 (s, 3H); 13C NMR (400 MHz, CDCl3) d 208.8,
154.1, 153.2, 140.3, 128.9, 127.4, 126.4, 115.8, 114.6, 73.9,
56.4, 55.7, 26.1, 20.4; MS (EI) m/z 284 (Mþ), 241, 124
(100), 95, 77; Anal. calcd for C18H20O3: C, 76.03; H, 7.09.
Found: C, 76.25; H, 7.34.
1.1.9. 3-Methyl-4-phenoxy-3-phenylbutan-2-one (7h).
The title compound was prepared by the above method,
using phenol instead of 4-methoxyphenol. Purification by
flash chromatography on silica gel (petroleum ether/EtOAc
97:3) afforded 7h (0.073 g, 70%) as a colorless oil: IR
760 cm21; H NMR (400 MHz, CDCl3) d 7.44–7.24 (m,
1
5H), 2.90 (d, J¼16.9 Hz, 1H), 2.78 (d, J¼16.9 Hz, 1H), 1.98
(s, 3H), 1.79 (s, 3H); 13C NMR (400 MHz, CDCl3) d 207.0,
138.6, 129.2, 128.2, 125.9, 117.4, 53.7, 28.3, 24.9, 20.3; MS
(EI) m/z 187 (Mþ), 144 (100), 118, 103, 91, 77; HRMS
(FAB) calcd for C12H14NO (MþþH) 188.1075, found
188.1085.
1
(film) 1708, 1598, 1495, 1240 cm21; H NMR (400 MHz,
CDCl3) d 7.38–7.22 (m, 7H), 6.90 (m, 3H), 4.50 (d,
J¼9.0 Hz, 1H), 4.19 (d, J¼9.0 Hz, 1H), 2.02 (s, 3H), 1.70
(s, 3H); 13C NMR (400 MHz, CDCl3) d 208.7, 158.9,
140.1, 129.3, 128.8, 126.3, 125.8, 120.9, 114.7, 72.9, 56.3,
26.1, 20.3; MS (EI) m/z 254 (Mþ), 118 (100), 94, 77; Anal.
calcd for C17H18O2: C, 80.28; H, 7.14. Found: C, 80.48; H,
7.38.
1.1.6.
4-Azido-3-methyl-3-phenylbutan-2-one
(7e).
Sodium azide (0.27 g, 4.2 mmol) was dissolved in distilled
water (0.2 mL). A solution of 3-methyl-2-methylene-3-
phenyloxetane (1) (0.066 g, 0.4 mmol) in DMF (0.6 mL)
was added. The mixture was stirred for 8 h at 1008C then
cooled to rt. H2O (6 mL) was added, and the reaction
mixture was extracted with Et2O (3£6 mL). The combined
organic extracts were dried (Na2SO4) and concentrated in
vacuo. Purification by flash chromatography on silica gel
(petroleum ether/EtOAc 97:3) afforded 7e (0.054 g, 65%)
1.1.10. 3-Methyl-3-phenyl-4-phenylsulfanyl-butan-2-one
(7i). Dry DMF (0.45 mL) was added to NaH (0.030 g,
1.2 mmol). Benzenethiol (0.13 mL, 1.2 mmol) was added
dropwise; then, a solution of 3-methyl-2-methylene-3-
phenyloxetane (1) (0.066 g, 0.4 mmol) in dry DMF
(0.30 mL) was added. The mixture was stirred for 4 h at
608C, then cooled to rt. H2O (6 mL) was added, and the
reaction mixture was extracted with Et2O (3£6 mL). The
combined organic extracts were dried (Na2SO4) and
concentrated in vacuo. Purification by flash chromatography
on silica gel (petroleum ether/EtOAc 97:3) afforded 7i
(0.11 g, 98%) as a colorless oil which crystallized in the
as a colorless oil: IR (film) 2099, 1705, 1598 cm21; H
1
NMR (400 MHz, CDCl3) d 7.40–7.23 (m, 5H), 3.80
(d, J¼12.4 Hz, 1H), 3.56 (d, J¼12.4 Hz, 1H), 1.97 (s,
3H), 1.65 (s, 3H); 13C NMR (400 MHz, CDCl3) d 208.8,
139.4, 129.0, 127.8, 126.3, 58.8, 56.3, 25.7, 19.2; MS (EI)
m/z 147, 118 (100), 105, 91, 77; Anal. calcd for C11H13N3O:
C, 65.01; H, 6.45; N, 20.68. Found: C, 65.23; H, 6.28; N,
20.82.
1
freezer: mp 388C; IR (film) 1703, 1481, 1088 cm21; H
NMR (400 MHz, CDCl3) d 7.36–7.11 (m, 10H), 3.52 (d,
J¼13.0 Hz, 1H), 3.48 (d, J¼13.0 Hz, 1H), 1.95 (s, 3H), 1.69
(s, 3H); 13C NMR (400 MHz, CDCl3) d 209.1, 140.8, 137.4,
129.7, 128.8, 127.5, 126.4, 126.0, 125.9, 56.5, 43.8, 25.8,
20.8; MS (EI) m/z 270 (Mþ), 227, 149 (100), 118, 91, 77;
Anal. calcd for C17H18OS: C, 75.51; H, 6.71. Found: C,
75.20; H, 6.41.
1.1.7. 4-Iodo-3-methyl-3-phenylbutan-2-one (7f). The
title compound was prepared by the above method using
sodium iodide instead of sodium azide. The reaction
mixture stirred for 9 h at 1008C in the dark and yielded 7f
(0.048 g, 40%) as a colorless oil: IR (film) 1703, 1352,
1
1209 cm21; H NMR (400 MHz, CDCl3) d 7.39–7.20 (m,
5H), 3.73 (d, J¼10.3 Hz, 1H), 3.57 (d, J¼10.3 Hz, 1H), 2.00
(s, 3H), 1.70 (s, 3H); 13C NMR (400 MHz, CDCl3) d 207.1,
140.1, 129.0, 127.8, 126.2, 55.6, 26.3, 22.9, 16.7; MS (EI)
m/z 245 (Mþ2CH3CO), 161 (Mþ2I), 118 (100), 91; Anal.
calcd for C11H13IO: C, 45.85; H, 4.55. Found: C, 46.10; H,
4.48.
1.1.11. 3-Methyl-4-phenylselanyl-3-phenylbutan-2-one
(7j). Dry DMF (0.60 mL) was added to NaH (0.034 g,
1.4 mmol). Solutions of benzeneselenol (0.09 mL, 0.8
mmol) in dry DMF (0.25 mL) and 3-methyl-2-methylene-
3-phenyloxetane (1) (0.066 g, 0.4 mmol) in dry DMF
(0.25 mL) were added successively. The mixture was stirred
for 14 h in the dark at rt. Water (6 mL) was then added, and
the reaction mixtures was extracted with Et2O (3£6 mL).
The combined organic extracts were dried (Na2SO4) and
concentrated in vacuo. Purification by flash chromatography
on silica gel (petroleum ether/EtOAc 95:5) afforded 7
(0.092 g, 71%) as a colorless oil: IR (film) 1704, 1476,
1436, 1351 cm21; 1H NMR (400 MHz, CDCl3) d 7.39–7.17
(m, 10H), 3.49 (d, J¼12.2 Hz, 1H), 3.39 (d, J¼12.2 Hz,
1H), 1.95 (s, 3H), 1.70 (s, 3H); 13C NMR (400 MHz,
CDCl3) d 209.3, 141.3, 133.0, 131.6, 128.9, 128.8,
127.5, 126.8, 126.3, 56.7, 38.8, 25.8, 21.4; MS (EI) m/z
318 (Mþ), 275, 197 (100), 157, 117, 91, 77; Anal. calcd
1.1.8. 3-Methyl-4-(4-methoxyphenoxy)-3-phenylbutan-
2-one (7g). Dry DMF (0.70 mL) was added to NaH
(0.050 g, 2.0 mmol). A solution of 4-methoxyphenol
(0.26 g, 2.0 mmol) in dry DMF (0.30 mL), and a solution
of 3-methyl-2-methylene-3-phenyloxetane (1) (0.066 g,
0.4 mmol) in dry DMF (0.25 mL) were successively
added dropwise. The mixture was stirred for 20 h at
1008C. The solution was then cooled to rt, and H2O
(6 mL) was added. The reaction mixture was extracted with
Et2O (3£6 mL), and the combined organic extracts were
dried (Na2SO4) and concentrated in vacuo. Purification by
flash chromatography on silica gel (petroleum ether/EtOAc