By using a phosphine oxide-catalyzed enantioselective double aldol reaction, we achieved the concise construction of C₂-symmetric 1,9-diarylnonanoids, enabling the synthesis of (−)-ericanone from p-hydroxybenzaldehyde in 6 steps with 65 % overall yield. The enantioselective double aldol reaction is useful for establishing C₂-symmetric 1,9-diaryl-3,7-dihydroxy-5-nonanones with a single operation. Furthermore, the use of o-nosyl-protected p-hydroxybenzaldehyde and a 4,4′-disubstituted BINAP dioxide catalyst dramatically improved the reactivity and selectivity in the double aldol reaction, enabling the total synthesis of (−)-ericanone with high yield and with excellent enantiopurity.

Asymmetric Michael addition of acyclic α-alkyl-β-keto esters with vinyl ketones catalyzed by a chiral lithium binaphtholate is described. Lithium binaphtholates, prepared from BINOL derivatives and inexpensive LiOH, effectively promoted the transformation of acyclic α-alkyl-β-keto esters in a highly enantioselective manner, affording Michael adducts bearing chiral quaternary carbon centers.