B. Furman et al. / Tetrahedron 64 (2008) 3103e3110
3109
(500 MHz, CDCl3) d: 7.27e7.16 (m, 5H), 4.56 (dd, J¼9.8,
1.3 Hz, 1H), 4.35 (d, J¼9.8 Hz, 1H), 4.26 (m, 1H), 3.21 (m,
1H), 2.95 (dd, J¼13.5, 7.4 Hz, 1H), 2.78 (dd, J¼13.5,
6.2 Hz, 1H), 2.27e2.13 (m, 2H), 1.90 (m, 1H), 1.67 (m,
1H), 1.48e1.30 (m, 4H), 0.75 (t, J¼7.4 Hz, 3H); 13C NMR
(125 MHz, CDCl3) d: 205.3, 138.9, 129.8, 127.8, 125.9,
106.0, 81.4, 81.3, 74.9, 42.5, 36.1, 30.1, 28.8, 28.6, 10.1;
HRMS calcd for C17H22O (Mþ): 242.1671, found: 242.1679;
HPLC (DAICEL CHIRALCEL OJ-H, 25 cmꢂ0.46 cm I.D.,
rate 0.5 mL/min, hex/IPA¼99:1) 6.9 min (97.7%), 8.3 min
(2.3%).
299.1418;
HPLC
(DAICEL
CHIRALCEL
OK,
25 cmꢂ0.46 cm I.D., rate 0.5 mL/min, hex/IPA¼99:1)
13.2 min (90.0%), 18.3 min (10.0%).
4.2.17. (2S,7S)-2-(4-Nitrophenyl)-7-phenyl-3-vinylidene-
oxepane (18b)
Chromatography (6:94 Et2O/hexane) afforded 48.0 mg
(75%), colorless oil. [a]D ꢀ56.8 (c 0.2, CH2Cl2); IR (neat)
2932, 1954, 1519, 1346, 1096, 851, 699 cmꢀ1 1H NMR
;
(500 MHz, CDCl3) d: 8.20e8.17 (m, 2H), 7.66e7.65 (m,
2H), 7.42e7.38 (m, 2H), 7.34 (m, 2H), 7.26 (m, 1H), 5.44
(s, 1H), 4.94 (dd, J¼10.7, 1.4 Hz, 1H), 4.84 (m, 1H), 4.76
(d, J¼10.5 Hz, 1H), 2.30 (m, 1H), 2.12e2.03 (m, 3H), 1.87
(m, 1H), 1.66 (m, 1H); 13C NMR (125 MHz, CDCl3) d:
207.1, 149.7, 147.1, 143.8, 128.3, 127.2, 126.8, 125.5,
123.3, 106.2, 80.6, 80.2, 76.6, 38.9, 29.1, 27.7; HRMS calcd
for C20H19NO3Na (MþNa)þ: 344.1257, found: 344.1273;
HPLC (DAICEL CHIRALCEL OJ-H, 25 cmꢂ0.46 cm I.D.,
rate 1.0 mL/min, hex/IPA¼95:5) 12.2 min (8.6%), 17.0 min
(91.4%).
4.2.14. (2R,7S)-7-Ethyl-2-phenethyl-3-vinylideneoxepane
(17e)
Chromatography (1:99 Et2O/hexane) afforded 45.6 mg
(89%), colorless oil. [a]D þ166.8 (c 0.1, CH2Cl2); IR (neat)
2927, 1953, 1454, 1090, 846, 698 cmꢀ1
;
1H NMR
(500 MHz, CDCl3) d: 7.30e7.14 (m, 5H), 4.75e4.60 (m,
2H), 4.07 (ddd, J¼9.9, 4.8, 2.1 Hz, 1H), 3.27 (ddd, J¼9.8,
4.6, 1.2 Hz, 1H), 2.81 (ddd, J¼15.7, 10.3, 5.6 Hz, 1H), 2.66
(ddd, J¼16.1, 10.1, 6.0 Hz, 1H), 2.30e2.10 (m, 2H), 2.0 (m,
1H), 1.91 (m, 1H), 1.86e1.67 (m, 2H), 1.59e1.34 (m, 4H),
0.94 (t, J¼7.4 Hz, 3H); 13C NMR (125 MHz, CDCl3) d:
205.3, 142.4, 128.4, 128.2, 125.6, 107.2, 81.3, 79.4, 75.2,
37.9, 36.1, 32.2, 30.2, 28.8, 28.7, 10.5; HRMS calcd for
C18H24O (Mþ): 256.1827, found: 256.1821; HPLC (DAICEL
CHIRALCEL OJ-H, 25 cmꢂ0.46 cm I.D., rate 0.5 mL/min,
hex/IPA¼99:1) 7.9 min (97.5%), 8.6 min (2.5%).
4.2.18. (2S,7R)-7-Phenyl-2-phenethyl-3-vinylideneoxepane
(18c)
Chromatography (3:97 Et2O/hexane) afforded 54.0 mg
(89%), colorless oil. [a]D ꢀ89.2 (c 0.3, CH2Cl2); IR (neat)
2927, 1953, 1453, 1096, 851, 698 cmꢀ1
;
1H NMR
(500 MHz, CDCl3) d: 7.39e7.12 (m, 10H), 4.76 (m, 1H),
4.70 (m, 1H), 4.46 (d, J¼10.1 Hz, 1H), 4.22 (m, 1H), 2.80
(m, 1H), 2.68 (m, 1H), 2.35e2.30 (m, 2H), 2.10e1.95 (m,
3H), 1.87 (m, 1H), 1.74 (m, 1H), 1.60 (m, 1H); 13C NMR
(125 MHz, CDCl3) d: 205.5, 144.5, 142.2, 128.5, 128.4,
128.2, 128.1, 126.8, 125.6, 106.9, 81.0, 79.2, 75.5, 38.8,
37.9, 32.1, 29.2, 28.6; HRMS calcd for C22H24O (Mþ):
304.1827, found: 304.1815; HPLC (DAICEL CHIRALCEL
OJ-H, 25 cmꢂ0.46 cm I.D., rate 0.5 mL/min, hex/IPA¼95:5)
12.4 min (92.7%), 14.6 min (7.3%).
4.2.15. (2S,7S)-7-Ethyl-2-(furan-2-yl)-3-vinylideneoxepane
(17f)
Chromatography (4:96 Et2O/hexane) afforded 35.3 mg
(81%), brown oil. [a]D þ117.8 (c 0.9, CH2Cl2); IR (neat)
2929, 1957, 1261, 1069, 849, 805 cmꢀ1
;
1H NMR
(400 MHz, CDCl3) d: 7.35 (dd, J¼1.8, 0.9 Hz, 1H), 6.31
(dd, J¼2.9, 1.8 Hz, 1H), 6.24 (dd, J¼3.3, 0.9 Hz, 1H), 5.17
(t, J¼1.8 Hz, 1H), 4.78 (ddd, J¼10.3, 3.3, 1.7 Hz, 1H), 4.71
(ddd, J¼10.3, 3.7, 2.0 Hz, 1H), 3.45 (m, 1H), 2.40e2.31 (m,
2H), 1.96 (m, 1H), 1.76 (m, 1H), 1.65e1.40 (m, 4H), 0.98
(t, J¼7.4 Hz, 3H); 13C NMR (100 MHz, CDCl3) d: 206.5,
154.9, 142.1, 109.9, 106.4, 105.0, 80.9, 75.9, 75.8, 35.8,
30.1, 29.1, 28.8, 10.4; HRMS calcd for C14H18O2 (Mþ):
218.1307, found: 218.1316; HPLC (DAICEL CHIRALCEL
OB-H, 25 cmꢂ0.46 cm I.D., rate 0.2 mL/min, hex/
IPA¼99:1) 18.3 min (98.9%), 21.4 min (1.1%).
4.2.19. (2R,6S)-6-Ethyl-2-phenyldihydro-2H-pyran-3(4H)-
one (19)
A stirred solution of 15a (26.0 mg, 0.12 mmol) in CH2Cl2
(5 mL) at ꢀ78 ꢁC was bubbled a stream of ozone for 5 min.
The color of the solution changed from colorless to pink to
blue, and the resulting solution was stirred for 20 min at
ꢀ78 ꢁC. Air was then passed through the reaction mixture until
the blue color disappeared. The DMS (0.30 mmol, 23 mg) was
added to the solution and the dry ice bath was removed and
the reaction mixture stirred at room temperature for 3 h. The sol-
vent was evaporated and the residue was chromatographed on
silica gel with 5% Et2O in hexane to furnish the ketone 19
(24 mg, 97%). [a]D ꢀ13.7 (c 0.3, CH2Cl2); IR (neat) 2966,
4.2.16. (2S,7S)-2,7-Diphenyl-3-vinylideneoxepane (18a)
Chromatography (3:97 Et2O/hexane) afforded 52.5 mg
(95%), yellow oil. [a]D ꢀ49.6 (c 0.2, CH2Cl2); IR (neat)
2928, 1954, 1449, 1067, 850, 697 cmꢀ1
;
1H NMR
(500 MHz, CDCl3) d: 7.51e7.25 (m, 10H), 5.38 (s, 1H),
4.87 (ddd, J¼10.3, 3.1, 1.6 Hz, 1H), 4.78 (m, 1H), 4.74 (d,
J¼10.5 Hz, 1H), 2.29 (m, 1H), 2.18 (m, 1H), 2.06e2.01 (m,
2H), 1.84 (m, 1H), 1.64 (m, 1H); 13C NMR (125 MHz,
CDCl3) d: 207.1, 144.4, 142.5, 128.2, 128.0, 127.1, 126.9,
126.1, 125.6, 106.9, 80.9, 80.0, 75.8, 39.0, 29.4, 27.7;
HRMS calcd for C20H20ONa (MþNa)þ: 299.1406, found:
1726, 1452, 1275, 1097, 698 cmꢀ1 1H NMR (500 MHz,
;
CDCl3) d: 7.37e7.28 (m, 5H), 4.90 (s, 1H), 3.78 (m, 1H), 2.73
(ddd, J¼15.7, 7.2, 4.9 Hz, 1H), 2.52 (ddd, J¼15.7, 9.3,
7.3 Hz, 1H), 2.16 (dddd, J¼15.8, 7.3, 3.7, 1.3 Hz, 1H), 2.05
(m, 1H), 1.75 (m, 1H), 1.65 (m, 1H), 1.02 (t, J¼7.5 Hz, 3H);
13C NMR (125 MHz, CDCl3) d: 208.5, 136.1, 128.2, 128.1,
127.3, 85.6, 77.5, 36.8, 30.7, 28.8, 9.9; HRMS calcd for