2,3-Dibromo-3-methyl-5-phenylpentanoic Acid

Molecules 1998, 3, M56

2(R,S),3(S,R)-2,3-Dibromo-3-methyl-5-phenyl-2-pentanoic Acid

Martin J. Stoermer^* and John T. Pinhey

Division of Organic Chemistry, School of Chemistry F11, The University of Sydney, N.S.W 2006, Australia.
^* Current address: Victorian College of Pharmacy, Monash University (Parkville Campus), 381 Royal Parade, Parkville, Victoria 3052, Australia. Phone: +61 3 990 39000, Fax: +61 3 99039582, e-mail: [email protected], http://synapse.vcp.monash.edu.au/martin/

Received: 27 February 1998 / Published: 6 March 1998

The general part of the experimental section [1] has been presented elsewhere. To a stirred solution of (Z)-3-methyl-5-phenyl-2-pentenoic acid (0.575 g, 3 mmol) in dry chloroform (10 ml) was added a solution of bromine (0.2 ml, 4 mmol) in dry chloroform (3 ml) dropwise. The mixture was stirred at room temperature for 16 hours and evaporated under reduced pressure to yield 2(R,S),3(S,R)-2,3-dibromo-3-methyl-5-phenyl-2-pentenoic acid (1.05 g, 99%) as an orange solid.

M.p. 115-8°

UV (ethanol) 206 (11390) nm.

IR (CDCl₃) 3300-2800(bs, OH), 1723 (s, C=O) cm^-1.

¹H-NMR (90 MHz, CDCl₃) 1.81-3.14 (4H, m, 2xCH₂), 1.96 (3H, s, CH₃), 4.69 (1H, s, -CHBr), 6.96-7.44 (5H, m, ArH), 9.68 (1H, bs, COOH).

¹³C-NMR (15 MHz, CDCl₃) 29.67 (CH₃), 32.40, 41.36 (CH₂), 54.93 (CHBr), 66.36 (C3), 126.1, 128.4, 128.4 (ArCH), 140.6 (quat, C1'), 172.3 (quat, C1).

EI-MS 352(M⁺+4, 1%), 350(M⁺+2, 2), 348 (M⁺, 2), 146(17), 145(67), 143(27), 131(28), 129(35), 128(23), 115(16), 105(16), 103(13), 92(49), 91(100).

Acknowledgment: The authors gratefully acknowledge financial support from the Australian Research Council and The University of Sydney.

References and Notes

1. 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.

Sample Availability: No sample available.