1-(Triphenylphosphoranylidene)acetone → 1-(N-Cbz-2-pyrrolidinyl)-1-buten-3-one

Participants

Reaction Steps

To a stirred solution of N-Cbz-L-prolinal (6.3 g, 27 mmol, from step 24d above) in 30 mL of benzene was added 9.42 g (29.6 mmol) of 1-triphenylphosphoranylidene-2-propanone (Aldrich) at room temperature. The reaction mixture was heated to reflux for 4 hr. The benzene was removed under vacuum, and the residue was dissolved in ether and cooled for 16 hr. The phosphine oxide by product was removed by filtration, and the solution was further purified by column chromatography on silica gel, eluting with 20% ethyl acetate in hexanes, to afford 4.4 g of the title product (69% yield).

Provenance & Evidence