(3aR,4R,5R,6aS)-4-formyl-2-oxohexahydro-2H-cyclopenta[b]furan-5-yl benzoate → (1S,5R,6R,7R)-7-benzoyloxy-6-[(1E)-3-oxo-1-octen-5-ynyl]-2-oxabicyclo[3.3.0]octan-3-one

Participants

Reaction Steps

A solution of 7.4 g of (1S,5R,6R,7R)-6-formyl-7-benzoyloxy-2-oxabicyclo[3.3.0]octan-3-one (E. J. Corey et al., J. Chem. Soc., 91, 5675 (1969)) and 10.3 g of the phosphorane prepared in Example (23b) in 200 ml of absolute toluene is stirred at room temperature for 5.5 hours. The reaction solution is concentrated in vacuo and the residue is chromatographed over silica gel by gradient elution in hexane/40% ethyl acetate. 9.7 g of the title compound are obtained.

Provenance & Evidence