Ytterbium triflate → HCID 66823396, compound

Participants

Reaction Steps

To a mixture of 2-(4′-chloro-4-cyclopropyl-2′-fluorobiphenyl-3-yl)-4,4,6,6-tetramethyl-1,5-dioxaspiro[2.4]heptan-7-one (18.20 g, 0.044 mol) and ytterbium triflate (2.40 g, 4.40 mmol) is added a solution of 5M lithium perchlorate (prepared from 46 ml diethyl ether and 24.40 g lithium perchlorate). The resulting suspension is stirred at room temperature for 3 days, then is diluted with diethyl ether (85 ml) and additional ytterbium triflate (7.80 g, 0.014 mol) is added. After stirring at room temperature for a further 3 days additional ytterbium triflate (13.63 g, 0.025 mol) is added, and the reaction mixture is stirred for 11 days. Finally, extra lithium perchlorate (24.40 g, 0.23 mol) is added in one portion, and the mixture is heated at 27° C. (internal temperature) for 1 day. The reaction mixture is partitioned between diethyl ether and distilled water, the two phases separated, and the aqueous phase is extracted with diethyl ether (×2). The organic fractions are combined, washed with brine then dried over magnesium sulphate. The suspension is filtered and the filtrate concentrated in vacuo. The crude material purified by flash column chromatography (10% ethyl acetate in hexanes as eluant) to afford an oil which is triturated with hexanes to afford 4-(4′-chloro-4-cyclopropyl-2′-fluorobiphenyl-3-yl)-2,2,6,6-tetramethylpyran-3,5-dione (4.78 g) as a white solid.

Provenance & Evidence