Scheme 6. Synthesis of bifluranol 1. Reagents and conditions: (a) CbCl (1.0 equiv.), Et₃N (1.3 equiv.), n-propanol, sealed tube, μW, 150 °C, 1 h, 92% yield; (b) pinacol (1.0 equiv.), Et₂O, r.t., 16 h; MgSO₄ (3.0 equiv.), r.t., 2 h, quant.; (c) (+)-sparteine (1.3 equiv.), sBuLi (1.3 equiv.), Et₂O, –78 °C, 5 h; 29 (1.5 equiv.), –78 °C, 2 h; r.t., Et₂O → CHCl₃; reflux, 15 h, 76% yield; (d) NaH (1.5 equiv.), THF, r.t., 75 min; CbCl (1.2 equiv.), THF, reflux, 24 h, >99% yield; (e) TMEDA (1.3 equiv.), sBuLi (1.3 equiv.), Et₂O, –78 °C, 1 h; (S)-30 (1.5 equiv.), –78 °C, 2 h; r.t., 14 h, 95% yield; (f) TBAF·3H₂O (3.0 equiv.), toluene, reflux, 3 h, 99% yield; (g) NBS (1.1 equiv.), MeCN, r.t., 21 h, 94% yield; (h) nBuLi (1.3 equiv.), THF, –78 °C, 30 min; NFSI (1.2 equiv.), –78 °C, 2 h; (j) BBr₃ (3.0 equiv.), CH₂Cl₂, –20 °C; 30 min; 4 °C, 16 h, 43% yield over 2 steps. CbCl = N,N-diisopropylcarbamoyl chloride, sBuLi = sec-butyllithium, TMEDA = N,N,N′,N′-tetramethylethylenediamine, TBAF·3H₂O = tetrabutylammonium fluoride trihydrate, NBS = N-bromosuccinimide, nBuLi = n-butyllithium, THF = tetrahydrofuran, NFSI = N-fluorobenzenesulfonimide.