1178
J. S. Yadav et al.
PAPER
IR (neat): 3446, 2922, 2854, 1102, 1021, 698 cm–1.
(0.02 g) and benzyl bromide (0.31 g, 1.81 mmol) were added se-
quentially and stirring was continued for 2 h at 0 °C then for 12 h at
reflux temperature. The reaction mixture was quenched by the ad-
dition of crushed ice flakes until a clear solution (biphasic) formed.
The reaction mixture was extracted with EtOAc (2 × 15 mL). The
organic extracts were washed with H2O (10 mL), brine (10 mL) and
dried over anhydrous Na2SO4. Evaporation of the solvents, fol-
lowed by column chromatography (hexane–EtOAc), afforded the
pure product 12.
1H NMR (CDCl3,300 MHz): d = 7.45–7.36 (m, 2 H), 7.34–7.19 (m,
8 H), 5.87–5.73 (m, 1 H), 5.48 (s, 0.5 H), 5.45 (s, 0.5 H), 5.14–5.03
(m, 2 H), 4.46 (s, 2 H), 4.16–3.74 (m, 3 H), 3.52–3.41 (m, 2 H),
2.26–2.14 (m, 2 H), 1.87–1.36 (m, 8 H).
ESI-MS: m/z = 397 [M + H]+, 419 [M + Na]+, 414 [M + NH4]+.
5-(2S,4S,6S)-6-[3-(Benzyloxy)propyl]-2-phenyl-1,3-dioxan-4-
yl-1-penten-4-one (9)
Yield: 589 mg (80%); colorless liquid; Rf = 0.3 (SiO2, EtOAc–hex-
ane, 10%); [a]D25 –15.1 (c 3.00, CHCl3).
IR (neat): 2921, 2853, 1103, 1022, 913, 697 cm–1.
1H NMR (CDCl3, 300 MHz): d = 7.44–7.38 (m, 2 H), 7.32–7.18 (m,
13 H), 5.9–5.76 (m, 1 H), 5.40 (s, 1 H), 5.12–5.02 (m, 2 H), 4.56 (d,
J = 11.3 Hz, 1 H), 4.46 (s, 2 H), 4.42 (d, J = 11.3 Hz, 1 H), 3.94–
3.82 (m, 1 H), 3.72–3.57 (m, 2 H), 3.51–3.40 (m, 2 H), 2.41–2.32
(m, 2 H), 2.04–1.93 (m, 1 H), 1.83–1.55 (m, 5 H), 1.43–1.25 (m,
2 H).
To a stirred solution of o-iodoxybenzoic acid (2.12 g, 7.6 mmol) in
DMSO (2 mL) was added the homoallyl alcohol 8 (1.5 g, 3.8 mmol)
in THF (8 mL). The solution was stirred for 4 h at 25 °C then the
mixture was filtered through celite. The filtrate was washed with
H2O (10 mL), brine (10 mL), dried over Na2SO4 and concentrated
in vacuo. Purification of the crude product by silica gel column
chromatography (hexane–EtOAc) afforded the ketone 9.
Yield: 1.17 g (79%); colorless liquid; Rf = 0.5 (SiO2, EtOAc–hex-
ane, 20%); [a]D25 +2.7 (c 2.00, CHCl3).
IR (neat): 2917, 2859, 1715, 1105, 1021, 699 cm–1.
13C NMR (CDCl3, 75 MHz): d = 138.8, 138.5, 134.5, 128.3, 128.2,
128.0, 127.9, 127.5, 127.4, 125.9, 117.2, 100.3, 76.4, 74.3, 73.8,
72.8, 70.5, 70.1, 39.8, 38.1, 36.7, 32.4, 25.3.
1H NMR (CDCl3,300 MHz): d = 7.50–7.37 (m, 2 H), 7.32–7.20 (m,
8 H), 5.96–5.87 (m, 1 H), 5.46 (s, 1 H), 5.2–5.07 (m, 2 H), 4.46 (s,
2 H), 4.30–4.21 (m, 1 H), 3.86–3.76 (m, 1 H), 3.50–3.41 (m, 2 H),
3.21–3.17 (m, 2 H), 2.88–2.80 (dd, J = 6.79, 16.24 Hz, 1 H), 2.55–
2.47 (dd, J = 5.85, 16.24 Hz, 1 H), 1.82–1.62 (m, 5 H), 1.46–1.29
(m, 1 H).
ESI-MS: m/z = 509.2 [M + Na]+.
Acknowledgment
13C NMR (CDCl3, 75 MHz): d = 206.1, 138.6, 130.2, 128.5, 128.3,
128.0, 127.5, 127.4, 126.0, 119.0, 100.5, 76.4, 73.0, 72.8, 70.1,
48.7, 48.2, 36.8, 32.5, 25.3.
N.N.K. thanks UGC, New Delhi for the award of a fellowship.
References
ESI-MS: m/z = 395.5 [M + H]+, 412.5 [M + NH4]+.
(1) (a) Kunze, B.; Jansen, R.; Reichenbach, H.; Hofle, G.
J. Antibiot. 1998, 51, 1075. (b) Jansen, R.; Kunze, B.;
Reichenbach, H.; Hofle, G. Eur. J. Org. Chem. 2000, 913.
(2) (a) Petri, A. F.; Sasse, F.; Maier, M. E. Eur. J. Org. Chem.
2005, 1865. (b) Petri, A. F.; Bayer, A.; Maier, M. E. Angew.
Chem. Int. Ed. 2004, 43, 5821. (c) Hilli, F.; White, J. M.;
Rizzacasa, M. A. Org. Lett. 2004, 6, 1289. (d) Su, Q.;
Panec, J. S. J. Am. Chem. Soc. 2004, 126, 2425.
(e) Nicolaou, K. C.; Kim, D. W.; Baati, R.; O’Brate, A.;
Giannakakou, P. Chem. Eur. J. 2003, 9, 6177. (f)Graetz, B.
R.; Rychnovsky, S. D. Org. Lett. 2003, 5, 3357. (g) Lewis,
A.; Stefanuti, I.; Swain, S. A.; Smith, S. A.; Tailor, R. J. K.
Org. Biomol. Chem. 2003, 1, 104. (h) Hilli, F.; White, J. M.;
Rizzacasa, M. A. Tetrahedron Lett. 2002, 43, 8507.
(i) Nicolaou, K. C.; Kim, D. W.; Baati, R. Angew. Chem. Int.
Ed. 2002, 41, 3701. (j) Kuhnert, S. M.; Maier, M. E. Org.
Lett. 2002, 4, 643. (k) Lewis, A.; Stefanuti, I.; Swain, S. A.;
Smith, S. A.; Tailor, R. J. K. Tetrahedron Lett. 2001, 42,
5549. (l) Bhattacharjee, A.; Seguil, O. R.; De brabander, J.
K. Tetrahedron Lett. 2001, 42, 1217. (m) Bhattacharjee, A.;
De brabander, J. K. Tetrahedron Lett. 2000, 41, 8069.
(3) Gao, Y.; Hanson, R. M.; Klunder, J. M.; Ko, S. Y.;
Masamune, H.; Sharpless, K. B. J. Am. Chem. Soc. 1987,
109, 5765.
(4R)-5-{(2S,4S,6S)-6-[3-(Benzyloxy)propyl]-2-phenyl-1,3-di-
oxan-4-yl}pent-1-en-4-ol (10)
To a stirred solution of ketone 9 (1.0 g, 2.53 mmol) in Et2O (30 mL)
was added LiI (3.4 g, 25.3 mmol) and the resulting mixture was
stirred at –40 °C for 5 min. After this period, the mixture was cooled
to –100 °C and LiAlH4 (0.964 g, 25.3 mmol) was added. The reac-
tion was stirred for 30 min and quenched with 10% potassium sodi-
um tartrate (8 mL) solution. The layers were separated and the
aqueous layer was extracted with Et2O (3 × 15 mL). The combined
organic layers were dried over Na2SO4 and concentrated under re-
duced pressure. The residue was purified by silica gel column chro-
matography (hexane–EtOAc) to provide a 4:1 diastereomeric
mixture of alcohols 10 and 11.
25
Yield: 0.89 g (89%); Rf = 0.2 (SiO2, EtOAc–hexane, 20%); [a]D
+2.3 (c 2.00, CHCl3).
IR (neat): 3446, 2922, 2854, 1102, 1021, 698 cm–1.
1H NMR (CDCl3, 200 MHz): d = 7.50–7.18 (m, 10 H), 5.91–5.70
(m, 1 H), 5.49 (s, 1 H), 5.16–5.03 (m, 2 H), 4.47 (s, 2 H), 4.14–3.74
(m, 3 H), 3.60–3.40 (m, 2 H), 2.33–2.15 (m, 2 H), 1.88–1.47 (m,
8 H).
13C NMR (CDCl3, 75 MHz): d = 138.6, 134.7, 128.6, 128.3, 128.1,
127.6, 127.4, 125.9, 117.5, 100.6, 76.6, 72.9, 70.2, 42.1, 41.9, 37.1,
32.5, 29.6, 25.3.
(4) Finan, J. M.; Kishi, Y. Tetrahedron Lett. 1982, 23, 2719.
(5) Vatele, J.-M. Tetrahedron Lett. 2006, 47, 715.
(6) Evans, D. A.; Gauchet-Prunet, J. A. J. Org. Chem. 1993, 58,
2446.
(7) (a) Ghosh, A. K.; Lei, H. J. Org. Chem. 2002, 67, 8783.
(b) Mori, Y.; Kuhara, M.; Takeuchi, A.; Suzuki, M.
Tetrahedron Lett. 1988, 29, 5419.
ESI-MS: m/z = 397 [M + H]+.
(4R)-4-Benzyloxy-5-{(2S,4S,6S)-6-[3-(benzyloxy)propyl]-2-phe-
nyl-1,3-dioxan-4-yl}pent-1-en (12)
To a suspension of NaH (60%, 80.0 mg, 3.33 mmol) in anhyd THF
(12 mL) was added, dropwise, a solution of alcohol 10 (600.0 mg,
1.51 mmol) in THF (6 mL) at 0 °C. To this reaction mixture TBAI
(8) Li, M.; O’Doherty, G. A. Org. Lett. 2006, 8, 6087.
Synthesis 2007, No. 8, 1175–1178 © Thieme Stuttgart · New York