(E)-1-Bromo-2-methyl-4-phenyl-1-butene
1
Division of Organic Chemistry, School of Chemistry F11, The University of Sydney, N.S.W 2006, Australia
2
Current address: Victorian College of Pharmacy, Monash University (Parkville Campus), 381 Royal Parade, Parkville, Victoria 3052, Australia
*
Author to whom correspondence should be addressed.
Molecules 1998, 3(3), M58; https://doi.org/10.3390/M58
Submission received: 27 February 1998
/
Published: 6 March 1998
(This article belongs to the Section Molbank Section of Molecules, 1997-2001)
The general part of the experimental section [1] has been presented elsewhere. 2(R,S),3(S,R)-2,3- Dibromo-3-methyl-5-phenyl-2-pentanoic acid (0.99 g, 3 mmol) was refluxed with potassium carbonate (2.0 g, 14 mmol) in acetone (40 ml) in the dark for 3 hours. The solvent was removed by distillation and the residue was partitioned between ether (100 ml) and water (100 ml). The ether extract was washed with brine (30 ml), dried (Na2SO4), filtered and evaporated under reduced pressure. The crude product was purified by flash chromatography (light petroleum) and then Kugelrohr distilled to yield (E)-1-bromo- 2-methyl-4-phenyl-1-butene (0.43 g, 68%) as a colourless oil.
B.p. 128°/2.5 mmHg
UV (ethanol) 259 (248), 254 (232) nm.
IR (CDCl3) 3027, 2941, 1632, 1496, 1454(s), 1039, 747 cm−1.
1H-NMR (400 MHz, CDCl3) 1.84 (3H, d, J 1.5 Hz, CH3), 2.40 (2H, dt, J 1.1, 7.8 Hz, CH2), 2.74 (2H, bt, J 7.8 Hz, CH2), 5.90 (1H, m, =CH), 7.12-7.34 (5H, m, ArH). Stereochemistry confirmed by n.O.e. difference spectroscopy. Irradiation at 1.84 produced no n.O.e. at 5.90 (1% at 2.74). Irradiation at 5.90 produced no n.O.e. at 1.84 (3% at 2.74, 3% at 2.40 and −21% at 7.16).
13C-NMR (15 MHz, CDCl3) 19.22 (CH3), 34.22, 40.13 (CH2), 101.9 (=CH), 126.0, 128.2 128.4 (ArCH),
141.0 (quat, C1' or C2), 141.2 (quat, C1' or C2).
EI-MS 226(M++2, 5%), 224(M+, 5), 146(43), 145(78), 144(38), 129(31), 128(28), 92(52), 91(100), 77(33).
Supplementary Materials
Acknowledgment
The authors gratefully acknowledge financial support from the Australian Research Council and The University of Sydney.
References and Notes
- Moloney, M.G.; Pinhey, J.T.; Stoermer, M.J. "Vinyl Cation Formation by Decomposition of Vinyl-lead Triacetates. The reactions of Vinylmercury and Vinyltin Compounds with Lead Tetraacetate.". J. Chem. Soc. Perkin Trans. 1 1990, 10, 2645. [Google Scholar] [CrossRef]
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MDPI and ACS Style
Stoermer, M.J.; Pinhey, J.T. (E)-1-Bromo-2-methyl-4-phenyl-1-butene. Molecules 1998, 3, M58. https://doi.org/10.3390/M58
AMA Style
Stoermer MJ, Pinhey JT. (E)-1-Bromo-2-methyl-4-phenyl-1-butene. Molecules. 1998; 3(3):M58. https://doi.org/10.3390/M58
Chicago/Turabian StyleStoermer, Martin J., and John T. Pinhey. 1998. "(E)-1-Bromo-2-methyl-4-phenyl-1-butene" Molecules 3, no. 3: M58. https://doi.org/10.3390/M58
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