Trifluoroacetic acid → HCID 25109291, compound

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Reaction Steps

The product from Example 3A (179 mg, 0.419 mmol) was cooled with an ice bath and treated with trifluoroacetic acid (6.5 mL, 84 mmol) for 1 minute, then concentrated under reduced pressure for about 2 minutes to remove excess trifluoroacetic acid. The residue was cooled with an ice bath, taken up in dichloromethane (50 mL) and basified with sodium hydroxide (10%). The organic layer was separated, dried with magnesium sulfate, and concentrated under reduced pressure. The resulting residue was chromatographed on a silica gel column eluting with ammonium hydroxide/methanol/dichloromethane (0.8/8/92) to provide the title product in enantiomerically enriched form: 1H NMR (CDCl3) δ 1.20-1.31 (m, 2H), 1.44-1.53 (m, 1H), 1.53-1.61 (m, 2H), 1.71-1.85 (m, 1H), 2.08-2.16 (m, 2H), 2.42 (t, 2H), 2.67-2.78 (m, 2H), 2.93-3.00 (m, 4H), 3.03-3.10 (m, 1H), 3.10-3.16 (m, 4H), 4.62-4.69 (m, 3H); MS (DCl/NH3) m/z 328 (M+H)+; [α]58920−106° (c 0.0038, methanol).

Provenance & Evidence