A facile method for the stereoselective preparation of (1E,3E)-4-substituted-1-amino-1,3-dienes via 1,4-elimination

Tetrahedron Letters

Volumn 48, Issue 35, 2007, Pages 6163-6166

  Tayama, Eiji ^a   Sugai, Sayaka ^a  

^a NIIGATA UNIVERSITY   (Japan)

Author keywords

1,4 Elimination; 1 Amino 1,3 dienes; Diels Alder reaction; Dienamides; Dienamines

Indexed keywords

ALKADIENE;

ARTICLE; CHEMICAL REACTION; STEREOCHEMISTRY;

ALNUS;

EID: 34547422888     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2007.06.140     Document Type: Article

References (17)

1. Oppolzer W. In: Trost B.M., and Fleming I. (Eds). Comprehensive Organic Synthesis Vol. 5 (1991), Pergamon, Oxford 331-333 Chapter 4.1.3.2
2. For review:. Hickmott P.W. Tetrahedron 40 (1984) 2989-3051
3. Oppolzer W., Bieber L., and Francotte E. Tetrahedron Lett. 20 (1979) 981-984
4. Oppolzer W., and Flaskamp E. Helv. Chim. Acta 60 (1977) 204-207
5. Oppolzer W., Fröstl W., and Weber H.P. Helv. Chim. Acta 58 (1975) 593-595
6. Jessup P.J., Petty C.B., Roos J., and Overman L.E. Org. Synth. 59 (1979) 1-7
7. Overman L.E., Taylor G.F., Petty C.B., and Jessup P.J. J. Org. Chem. 43 (1978) 2164-2167
8. Tayama E., Sugai S., and Hara M. Tetrahedron Lett. 47 (2006) 7533-7535
9. Tayama E., and Sugai S. Synlett (2006) 849-852
10. 2 (1 atm), Lindlar cat., quinoline, benzene, rt]. For more details, see Supplementary data.
11. Reaction procedure: A solution of 1a (698 mg, 2.82 mmol) in ether (12 mL) was treated with a 1.6 M hexane solution of n-BuLi (2.6 mL, 4.2 mmol) at 0 °C and the mixture was stirred for 3 h at 0 °C and for 1 h at room temperature. The resulting mixture was quenched with water and extracted with ether. The combined extracts were washed with brine, dried over sodium sulfate, and concentrated. The residue was purified by chromatography on pH-controlled silica gel (hexane as eluent) to afford 2a (582 mg, 96% yield) as a pale yellow oil.
12. Condensation of N-methylaniline and trans-oct-2-en-1-nal (benzene, reflux, 3 h) gave 1a in 57% yield as a mixture of stereoisomers [(1E,3E):(1E,3Z) = 6:4].
13. The presence of aliphatic amines might suppress the favorable 1,4-elimination reaction. For example, the reaction of 1a using LDA (THF, 0 °C, 2 h, then rt, 2 h), which affords diisopropylamine after reaction, gave 2a in lower yield and stereoselectivity [70% yield, (1E,3E):(1Z,3E) = 84:16].
14. This type of intermediate has been claimed to give the (1Z,3E)-1,3-dienyl ethers. For more details, see Ref. 5.
15. Prepared from N-Boc-aniline by the similar procedures to those described for 1a. For more details, see Supplementary data.
16. Reaction procedure: A solution of 3a (147 mg, 0.416 mmol) in ether (2.5 mL) was treated with a 0.99 M THF solution of NaHMDS (0.63 mL, 0.62 mmol) at 0 °C. The mixture was stirred for 3 h at room temperature and quenched with water at 0 °C. Extractive workup and purification of the residue by chromatography on silica gel (hexane:ethyl acetate = 20:1 to 10:1 as eluent) gave 4a (94.8 mg, 71% yield) as a colorless gum.
17. 3H-4H = 11.2 Hz. For more details, see Supplementary data.