Diethyl Ether → HCID 67468545, compound

Participants

Reaction Conditions

Reaction Steps

NaH (1.89 g, 47.3 mmol) was added in small portions to a mixture of tert-butyl 4-oxospiro[chroman-2,4′-piperidine]-1′-carboxylate (3.0 g, 9.5 mmol), Et2O (75 mL), and MeOH (120 μL) at rt. The mixture was allowed to stir for 1 h before ethyl formate (9.2 mL, 110 mmol) was added dropwise. The mixture was allowed to stir at 25° C. overnight before it was quenched with 1M aqueous HCl. The layers were separated and the aqueous layer was extracted with ethyl acetate (3×). The combined organics were washed with brine, dried over sodium sulfate, and concentrated in vacuo. Column chromatography (0-100% ethyl acetate in hexanes) provided tert-butyl 3-(hydroxymethylene)-4-oxospiro[chroman-2,4′-piperidine]-1′-carboxylate (1.2 g, 36%) as a light yellow solid. ESI-MS m/z calc. 345.2. found 246.2 (M+1-Boc)+; Retention time: 2.62 minutes (4 min run). 1H NMR (400 MHz, CDCl3) δ 15.13 (d, J=8.3 Hz, 1H), 7.93 (d, J=8.1 Hz, 1H), 7.88 (dd, J=7.8, 1.5 Hz, 1H), 7.50-7.44 (m, 1H), 7.06 (t, J=7.5 Hz, 1H), 6.96 (d, J=8.2 Hz, 1H), 4.10-3.95 (m, 2H), 3.25-3.15 (m 2H), 2.15 (d, J=12.7 Hz, 2H), 1.80-1.66 (m, 2H), 1.47 (s, 9H).

Provenance & Evidence