Phenylacetylene → N-Boc-pyrrolidine

Participants

Reaction Conditions

Reaction Steps

A solution of 6.9 ml (62.9 mmol) phenylacetylen in 120 ml THF was treated at −25° C. with 39.3 ml (62.9 mol) n-butyllithium (1.6M in hexane). The reaction was kept at −25° C. for 20 min, then dropped to a solution of 2.94 g (12.6 mmol) crude (2S,4S)-4-Chloro-2-formyl-pyrrolidine-1-carboxylic acid tert-butyl ester in 100 ml THF which was cooled to −25° C. After 45 min the reaction was neutralized with 100 ml of an aqueous 10% KHSO4 solution. The mixture was extracted with aqueous 10% KHSO4/Et2O (3×). The organic phases were washed with aqueous saturated 10% NaCl, dried (Na2SO4), evaporated and purified by flash-chromatography on silicagel (toluene/acetonitrile 195:5 to 9:1) to give 0.58 g (14%) of (2S,4S)-4-Chloro-2-((R) or (S)-1-hydroxy-3-phenyl-prop-2-ynyl)-pyrrolidine-1-carboxylic acid tert-butyl ester, MS: 336 (MH+)

Provenance & Evidence