Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl ester → HCID 57845336, compound

Participants

Reaction Steps

To a solution of (±)-4-methylbenzyl 3-fluoro-4-oxopiperidine-1-carboxylate (40 g, 150 mmol) in toluene (200 mL) at RT was added (carbethoxymethylene)triphenylphosphorane (63.0 g, 181 mmol) and the reaction mixture stirred for 1 h. The reaction mnixture was concentrated and purified by silica gel chromatography (gradient elution: 10% to 20% EtOAc in hexanes) to give the olefins (±)-4-methylbenzyl (E)-4-(2-ethoxy-2-oxoethylidene)-3-fluoropiperidine-1-carboxylate and (±)-4-methylbenzyl (Z)-4-(2-ethoxy-2-oxoethylidene)-3-fluoropiperidine-1-carboxylate (41.0 g, 78% yield, 3 steps) as a 3:1 E:Z mixture. This mixture was utilized directly in the next step. A small sample of the mixture was separated by silica gel chromatography for characterization purposes.

Provenance & Evidence