Fig. 3: Substrate scope of alkyl spirocyclic 1,3-diketons.

^aAll reactions were run on a 0.1 mmol scale; isolated yields; the ee value of (S)-5 were determined by UPC² or GC analysis on a chiral stationary phase; the ee value of 6 was determined by UPC² or HPLC analysis after acetylation with acryloyl chloride; dr values were determined via ¹H NMR analysis of the reaction mixtures; s = ln[(1 − conv)(1 – ee₁)]/ln[(1 − conv)(1 + ee₁)], conv = ee₁/(ee₁+ ee₂). ^bL2 was used instead of L4. ^cEt₃N (0.5 equiv.) was used instead of K₂HPO₄. ^dAfter oxidized.