HCID 10834141, compound → HCID 10155221, compound

Participants

Reaction Steps

Under nitrogen, 16.3 mL (149 mmol) of titanium(IV) chloride was slowly added to a suspension of 19.5 g (298 mmol) of zinc dust in 500 mL of anhydrous THF at -78° C. The resulting mixture was allowed to warm to ambient temperature and then to stir at reflux for 45 minutes. The reaction was cooled to ambient temperature prior to the addition of 19.27 g (49.6 mmol) of neat 1-(4-fluorophenyl)-2-[1-[2-[4-(methylsulfonyl)phenyl]-2-oxoethyl]cyclobutan-1-yl]ethan-1-one (prepared in Step 6) by syringe. The reaction was allowed to stir at ambient temperature overnight, filtered through celite, and concentrated in vacuo. The residue was partitioned between ethyl acetate and water; the ethyl acetate phase was washed with brine, dried (MgSO4), and concentrated in vacuo. Purification by silica gel chromatography (Waters Prep-500A) with ethyl acetate/hexane (20:80) gave 13.5 g (76%) of 6-(4-fluorophenyl)-7-[4-(methylsulfonyl)phenyl]spiro[3.4]oct-6-ene as a colorless solid: mp 123°-124° C.; NMR (CDCl3) δ1.85-1.98 (m, 2H), 2.08 (t, J=7 Hz, 4H), 2.98 (s, 4H), 3.04 (s, 3H), 6.92 (t, J=9 Hz, 7.05-7.13 (m, 2H), 7.30 (t, J=8 HZ, 2H), 7.75 (t, J=8 Hz, 2H). MS (FAB) m/e 357 (M+H). Anal. Calc'd for C21H21 OF2S: C, 70.76; H, 5.94; F, 5.53; S, 8.99. Found: C, 70.76; H, 6.10; F, 5.20; S, 8.96.

Provenance & Evidence