5372
G. Mao et al. / Tetrahedron Letters 46 (2005) 5369–5372
J. Am. Chem. Soc. 1992, 114, 7578–7579; (d) Sieburth, S.
M.; Fensterbank, L. J. Org. Chem. 1992, 57, 5279–5281.
Isolated yield 61% (271 mg). IR (neat) 1673 cmꢀ1 (C@O);
1H NMR (CDCl3, TMS): d 1.01–1.09 (m, 12H), 2.26–2.49
(m, 6H), 2.66–2.79 (m, 2H), 9.59 (s, 2H); 13C NMR
(CDCl3, TMS): d 11.8, 13.7, 18.5, 25.7, 143.5, 157.4, 192.3;
HRMS calcd for C14H22O2 222.1620, found 222.1611.
20. Xi, Z.; Song, Q. J. Org. Chem. 2000, 65, 9157–9159.
21. Typical procedure for the preparation of 1,6-diol 2a. To a
50 mL Schlenk tube containing 2.0 mmol of 1a in 20 mL
of ethyl ether, 1.0 mmol of LiAlH4 was added at 0 ꢁC.
After the reaction mixture was stirred at 0 ꢁC for 1h, the
reaction was quenched with 6 N H2SO4 and extracted with
ether. The extract was washed with NaHCO3, water and
brine and dried over Na2SO4. The solvent was then
evaporated in vacuo and the residue was purified by
column chromatograph (silica gel, diethyl ether/petroleum
ether in 1:3) to afford the product 2a. White solid. Isolated
yield 82% (371mg). Mp 70–71 ꢁC; 1H NMR (CDCl3,
TMS): d 0.84 (t, J = 7.5 Hz, 6H), 1.04 (t, J = 7.5 Hz, 6H),
1.74–1.97 (m, 2H), 2.08–2.48 (m, 6H), 3.61–3.83 (m, 2H),
3.91–4.20 (m, 4H); 13C NMR (CDCl3, TMS): d 12.2, 13.5,
22.4, 23.2, 61.9, 136.1, 138.6; HRMS calcd for
[C14H26O2Na]+ 249.1825, found 249.1821.
8. For a recent account on reaction chemistry of 1,4-dilithio-
1,3-dienes, see: Xi, Z. Eur. J. Org. Chem. 2004, 2773–2781;
see also: Foubelo, F.; Yus, M. Curr. Org. Chem. 2005, 9,
459–490; Varela, J. A.; Saa, C. Chem. Rev. 2003, 103,
3787–3801.
9. Xi, Z.; Song, Q.; Chen, J.; Guan, H.; Li, P. Angew. Chem.,
Int. Ed. 2001, 40, 1913–1916.
10. Song, Q.; Chen, J.; Jin, X.; Xi, Z. J. Am. Chem. Soc. 2001,
123, 10419–10420.
11. Chen, J.; Song, Q.; Xi, Z. Tetrahedron Lett. 2002, 43,
3533–3535.
12. Song, Q.; Li, Z.; Chen, J.; Wang, C.; Xi, Z. Org. Lett.
2002, 4, 4627–4629.
13. Chen, J.; Song, Q.; Li, P.; Guan, H.; Jin, X.; Xi, Z. Org.
Lett. 2002, 4, 2269–2271.
14. Li, G.; Fang, H.; Xi, Z. Tetrahedron Lett. 2003, 44, 8705–
8708.
15. (a) Fang, H.; Li, G.; Mao, G.; Xi, Z. Chem. Eur. J. 2004,
10, 3444–3450; (b) Fang, H.; Song, Q.; Wang, Z.; Xi, Z.
Tetrahedron Lett. 2004, 45, 5159–5162.
16. Wang, C.; Song, Q.; Xi, Z. Tetrahedron 2004, 60, 5207–
5214.
17. Wakefield, B. J. Organolithium Methods; Academic Press:
London, 1988, pp 82–88.
18. For a reaction of dilithio reagents with DMF affording
cyclic compounds, see: Deniau, E.; Enders, D. Tetra-
hedron Lett. 2002, 43, 8055–8058.
19. Typical procedure for the preparation of 1,6-dial 1a. To a
50 mL Schlenk tube containing 2.0 mmol of 1,2,3,4-
tetraethyl-1,4-dilitho-1,3-diene 3a in 20 mL diethyl ether
at ꢀ78 ꢁC was added 5.0 mmol of DMF. After the
reaction mixture was stirred at ꢀ78 ꢁC for 1h, the
reaction was quenched with saturated aqueous NaHCO3
and extracted with ether. The extract was washed with
water and brine and dried over MgSO4. The solvent was
then evaporated in vacuo and the residue was purified by
column chromatograph (silica gel, diethyl ether/petroleum
ether in 1:30) to afford the product 1a. Colourless liquid.
22. X-ray crystallographic data for 2h: A colourless crystal
having approximate dimensions of 0.40 · 0.35 · 0.08 mm
was mounted on a glass fibre. X-ray data were collected on
a Rigaku RAXIS RAPID IP diffractometer with graphite-
˚
monochromated Mo/Ka radiation (k = 0.71073 A).
C22H24F2O2, fw = 358.41, triclinic, space group P-1,
˚
˚
˚
a = 12.061(1) A, b = 13.239(2) A, c = 6.963(1) A, V =
965.6(2) A ; Z = 2; Dcalcd = 1.233 g cmꢀ3
; R1 = 0.0595,
3
˚
wR2 = 0.1389. CCDC 268480.
23. X-ray crystallographic data for 6: A colourless crystal
having approximate dimensions of 0.40 · 0.30 · 0.15 mm
was mounted on a glass fibre. X-ray data were collected
on a Rigaku RAXIS RAPID IP diffractometer with grap-
˚
hite-monochromated Mo/Ka radiation (k = 0.71073 A).
C29H25F3O, fw = 446.49, triclinic, space group P-1,
˚
˚
˚
a = 10.728(1) A, b = 12.137(2) A, c = 9.271(1) A, V =
1140.2(3) A ; Z = 2; Dcalcd = 1.301 g cmꢀ3; R1 = 0.0486,
3
˚
wR2 = 0.1133. CCDC 268382.