Reaction SMILES: [O:1]=[C:2]([CH:4]=[C:5]([CH3:7])C)[CH3:3].CCCC[N+:12]([CH2:21][CH2:22]CC)([CH2:17][CH2:18][CH2:19]C)CCCC.[F-]>>[NH:12]1[CH:17]=[CH:18][CH:19]=[C:21]1[CH2:22][CH2:7][CH2:5][CH2:4][C:2](=[O:1])[CH3:3]
Reactant: CCCC[N+](CCCC)(CCCC)CCCC
Reactant: CC(=O)C=C(C)C
Agent: [F-]
Product: CC(=O)CCCCc1ccc[nH]1
Yield: 47 %

Procedure:
The synthesis of an 8-bromo-substituted Western half is shown in Scheme 5. Treatment of pyrrole-2-carobxaldehyde with one molar equivalent of NBS at −78° C. gave 4-bromopyrrole-2-carboxaldehyde 17 (Anderson, J. H.; Lee, S.-F. Can. J. Chem. 1965, 43, 409-414) in 55% yield after crystallization. This method of bromination of pyrrole-2-carboxaldehyde is superior to a reported method that uses Br2 (Anderson, J. H.; Lee, S.-F. Can. J. Chem. 1965, 43, 409-414). It should be mentioned here that careful handing of the crude product is required: the off-white solid often turns reddish (irrespective of preparation using Br2 or NBS), which complicates crystallization. Following a procedure for the synthesis of 2-(2-nitroethyl)pyrroles (Taniguchi, M. et al., J. Org. Chem. 2001, 66, 7342-7354), treatment of 17 with excess nitromethane, sodium acetate and methylamine hydrochloride at room temperature for 16 h followed by reduction of the reaction mixture with NaBH4 gave 4-bromo-2-(2-nitroethyl)pyrrole (18) in variable yields (32-48%). However, 18 was found to explode (CAUTION), which caused us to avoid handling this compound. Thus, we considered protection of the pyrrole nitrogen in 4-bromo-pyrrole-2-carboxaldehyde (17) for two purposes: (1) to render 4-bromo-2-(2-nitroethyl)pyrrole (18) as a stable compound, and (2) for efficient palladium-coupling in the latter part of the 8-ethynyl Western half synthesis. Considering the facile conditions for removal of a p-toluenesulfonyl group coupled with the crystalline nature of 2-(2-nitroethyl)-N-p-tosylpyrroles, N-tosylation (Tietze, L. F. et al., Synthesis 1996, 851-857) of compound 17 was carried out. Thus, treatment of 17 with NaH at 0° C. for 1 h followed by quenching with p-toluenesulfonyl chloride gave 17-Ts as a pale yellow crystalline solid in 68% yield. Following a reported procedure for the synthesis of 2-(2-nitrovinyl)-N-p-tosylpyrroles (Hamdan, A.; Wasley, J. W. F. Synth. Commun. 1985, 15, 71-74), a mixture of 17-Ts, excess nitromethane and ammonium acetate was refluxed for 3 h. The crude product was satisfactorily pure as evidenced by NMR spectroscopy and was directly used in the next step. NaBH4 reduction of the crude product in the presence of Montmorillonite K10 (Bahulayan, D. et al., J. Org. Chem. 2003, 68, 5735-5738), or silica gel (Ptaszek, M. et al., Org. Process Res. Dev. 2005, 9, 651-659) at room temperature afforded 2-(2-nitroethyl)-N-p-tosylpyrrole 18-Ts as a white solid in 40% or 58% yield, respectively. Michael addition of 18-Ts with mesityl oxide in the presence of TBAF (Battersby, A. R. et al., J. Chem. Soc., Perkin Trans. 1 1984, 2725-2732) and 3 Å molecular sieves gave the detosylated pyrrole-hexanone 19 in 47% yield. The p-toluenesulfonyl group is known to be cleaved by TBAF (Yasuhara, A.; Sakamoto, T. Tetrahedron Lett. 1998, 39, 595-596). Reduction (Ptaszek, M. et al., Org. Process Res. Dev. 2005, 9, 651-659) of 19 with excess zinc dust and HCOONH4 in THF at room temperature gave the 8-bromo Western half 20 in 45% yield.