“…Since the double-bond geometry was inconsequential for the subsequent steps,cleavage of the silyl ether and iodination was carried out without further separation of the isomers to give iodide 8 in good yield on multigram scale.Initial attempts to establish agold(I)-catalyzed addition of p-methoxyphenol (6)t o7 were unsuccessful due to ac ompeting enyne cyclization. Thei ntermediate bromo enol ether, which is surprisingly stable to flash-column chromatography on silica gel, was then converted into 13 by dihydroxylation of the sterically less hindered olefin using freshly prepared AD-mix-a [K 2 OsO 4 ·2 H 2 O, (DHQ) 2 Phal, K 2 CO 3 ,K 3 Fe(CN) 6 ]a nd subsequent intramolecular displace-ment of the secondary alcohol via the corresponding mesylate.S ince low yields were encountered in aN egishi crosscoupling reaction between iodide 8 and enol ether 13,w e considered the B-alkyl Suzuki-Miyaura coupling reaction [11] as av iable alternative.U nder the optimized reaction conditions (5 mol %SPhos Pd G2, 5mol %SPhos,Cs 2 CO 3 ,THF, DMF,H 2 O, 40 8 8C), coupling of 11 with 13 proceeded efficiently to afford the cyclization precursor 5 in excellent yield (85 %, 5. [10] Extensive experimentation revealed that the reaction proceeded best in N,N-dimethylformamide (DMF;1.0 m) at 70 8 8C, employing excess phenol (10 equiv) and cesium carbonate as base (3 equiv).…”