1922
S. Raghavan, A. Rajender / Tetrahedron Letters 45 (2004) 1919–1922
S. V.; Soloshonok, V. A.; Sorochinsky, A. E.; Viani, F.;
Zanda, M. Tetrahedron 1999, 55, 3025.
Chemistry; Trost, B. M., Fleming, I., Eds.; Pergamon:
Oxford, 1991; Vol. 7, p 193.
8. McKay, W. R.; Proctor, G. R. J. Chem. Soc., Perkin
Trans. 1 1981, 2435.
9. The structures were assigned to 4s and 4a by comparison
15. Representative procedure for compound 21. To the
solution of 18 (664 mg, 1.2 mmol) in acetonitrile (6 mL)
cooled at 0 °C was added triethylamine (364 mg, 3.6 mmol)
followed by trifluoroacetic anhydride (1.26 g, 6 mmol) and
stirred for 50 min. An aq 5% NaHCO3 solution (2 mL) was
added at 0 °C and stirred for another 20 min. The reaction
mixture was then extracted with benzene (10 mL), washed
successively with water, brine, dried over Na2SO4 and
used directly in the next step. Reaction with ethyl(triphen-
ylphosphoranilidine)acetate (498 mg, 1.2 mmol) at rt for
30 min afforded the unsaturated ester. The solvent was
removed under reduced pressure to afford the residue,
which was purified by column chromatography using
EtOAc/petroleum ether (1:9, v/v) as the eluent to afford
1
of their H NMR data with sulfoxides 25s and 25a. The
structure of 25s was unambiguously assigned by X-ray
crystallography of the related p-nitrobenzenesulfonamide
derivative. Refer: Raghavan, S.; Rajender, A.; Joseph, S.
C.; Rasheed, M. A.; Ravikumar, K. Tetrahedron: Asym-
metry 2004, 15, 365.
O
S
NHTs
O
S
NHTs
Ph
Ph
Ph
Ph
25s
25a
the a,b-unsaturated ester 21 (449 mg, 0.9 mmol) in 75%
25
yield (for the two steps). Solid. Mp 59–61 °C. ½aꢀ +58.7°
D
(c 2.3, CHCl3). 1H NMR (200 MHz, CDCl3) d (ppm) 7.63
(d, J ¼ 8:2 Hz, 2H), 7.39–7.2 (m, 7H), 6.54 (dd, J ¼ 15:6,
5.2 Hz, 1H), 5.76–5.56 (m, 3H), 5.08–4.93 (m, 2H), 4.56
(m, 1H), 4.12 (q, J ¼ 6:7 Hz, 2H), 3.18 (ddd, J ¼ 15:6,
11.1, 5.9 Hz, 1H), 2.92 (ddd, J ¼ 15:6, 10.4, 5.9 Hz, 1H),
2.56–2.16 (m, 6H), 2.06–1.91 (m, 4H), 1.24 (t, J ¼ 6:7 Hz,
3H). 13C NMR (75 MHz, CDCl3) d (ppm) 14.6, 21.5, 21.9,
36.0, 39.5, 45.2, 55.8, 61.0, 73.0, 117.7, 124.3, 126.8, 127.7,
128.7, 129.1, 130.2, 134.8, 137.5, 140.1, 144.0, 144.7, 165.9.
MS (FAB) 500 [M+H]þ. Anal. Calcd for C27H36NO6S: C,
64.91; H, 6.66; N, 2.80; S, 6.42. Found: C, 65.08; H, 6.85;
N, 2.71; S, 6.46.
Com-
pound
C2H d
(ppm)
Com-
pound
C2H d
(ppm)
25s
25a
4.38
4.52
4s
4a
4.36
4.51
10. (a) Raghavan, S.; Rasheed, M. A.; Joseph, S. C.;
Rajender, A. J. Chem. Soc., Chem. Commun. 1999, 1845;
(b) Raghavan, S.; Ramakrishna Reddy, S.; Tony, K. A.;
Naveen Kumar, Ch.; Varma, A. K.; Nangia, A. J. Org.
Chem. 2002, 67, 5838; (c) Raghavan, S.; Joseph, S. C.
Tetrahedron: Asymmetry 2003, 14, 101; (d) Raghavan, S.;
Tony, K. A. J. Org. Chem. 2003, 68, 5002; (e) Raghavan,
S.; Ramakrishna Reddy, S. J. Org. Chem. 2003, 68, 5754;
(f) Raghavan, S.; Rasheed, M. A. Tetrahedron: Asymme-
try 2003, 14, 1371; (g) Raghavan, S.; Rajender, A.
Tetrahedron: Asymmetry 2003, 14, 2093; (h) Raghavan,
S.; Rajender, A. J. Org. Chem. 2003, 68, 7094; (i)
Raghavan, S.; Joseph, S. C. Tetrahedron Lett. 2003, 44,
6713; (j) Raghavan, S.; Ramakrishna Reddy, S. Tetra-
hedron Lett. 2003, 44, 7459; (k) Raghavan, S.; Joseph, S.
C. Tetrahedron Lett. 2003, 44, 8237.
11. Raghavan, S.; Rajender, A.; Rasheed, M. A.; Rama-
krishna Reddy, S. Tetrahedron Lett. 2003, 44, 8253.
12. (a) Caturla, F.; Najera, C. Tetrahedron Lett. 1997, 38,
3789; (b) Costa, A.; Najera, C. Tetrahedron: Asymmetry
2001, 12, 2205.
13. For excellent review, refer to (a) Schuster, M.; Blechert, S.
Angew. Chem., Int. Ed. 1997, 36, 2036; (b) Schuster, M.;
Blechret, S. Angew. Chem. 1997, 109, 2124; (c) Furstner,
A. Top. Catal. 1997, 4, 285; (d) Armstrong, S. K. J. Chem.
Soc., Perkin Trans. 1 1998, 371.
16. (a) Overkleeft, H. S.; Pandit, U. K. Tetrahedron Lett. 1996,
37, 547; (b) Huwe, C. M.; Blechert, S. Synthesis 1997, 61.
17. Representative procedure for compound 22. Bis(tricy-
clohexylphophine) benzylideneruthenium(IV)dichloride
G1 (25 mg, 0.032 mmol) was added to a solution of diene
(324 mg, 0.65 mmol) in toluene (13 mL) and refluxed for
16 h, when TLC revealed the complete consumption of the
starting material. The solvent was removed under reduced
pressure. Column chromatography of the residue using
EtOAc/petroleum ether (1:4, v/v) as the eluent afforded the
product (207 mg, 0.52 mmol) in 80% yield. Solid. Mp 75–
25
D
1
76 °C. ½aꢀ )119.0° (c 0.75, CHCl3). H NMR (200 MHz,
CDCl3) d (ppm) 7.67 (d, J ¼ 8:9 Hz, 2H), 7.36–7.16 (m,
7H), 5.74 (dd, J ¼ 9:7, 4.5 Hz, 1H), 5.66–5.54 (m, 2H),
4.48 (m, 1H), 3.77 (dd, J ¼ 14:9, 5.2 Hz, 1H), 3.08 (ddd,
J ¼ 14:9, 11.9, 5.2 Hz, 1H), 2.42 (s, 3H), 2.20–1.60 (m,
7H). 13C NMR (75 MHz, CDCl3) d (ppm) 21.2, 21.5, 29.7,
38.0, 41.4, 50.2, 72.7, 125.5, 126.5, 127.2, 127.3, 128.0,
128.5, 129.5, 138.1, 140.5, 143.2, 170.1. MS (FAB) 400
[M+H]þ. Anal. Calcd for C27H25NO4S: C, 66.14; H, 6.31;
N, 3.51; S, 8.02. Found: C, 66.03; H, 6.55; N, 3.41; S, 8.07.
18. Stragies, R.; Blechert, S. Tetrahedron 1999, 55, 8179.
19. Bach, T.; Brummerhol, H.; Harms, K. Chem. Eur. J. 2000,
6, 3848.
14. (a) Sugihara, H.; Tanikaya, R.; Kaji, A. Synthesis 1978,
881; (b) Pummerer, R. Chem. Ber. 1909, 42, 2282; (c)
Kennedy, M.; McKervey, M. In Comprehensive Organic