The asymmetric synthesis and a formal asymmetric synthesis of (+)-strictifolione are
described. As key step in both approaches the Julia-Kocienski olefination to create
an E-configured alkene was used. The anti-1,3-diol moiety was synthesized by employing a SAMP-hydrazone α,α′-bisalkylation/deoxygenation
protocol and the stereocentre of the lactone unit is based on an enzymatic reduction
with baker’s yeast. Alternatively, a lactone precursor could be efficiently synthesized
by a (S)-proline catalyzed α-oxyamination of pent-4-enal.
asymmetric synthesis - enzymatic reduction - hydrazones - natural products - organocatalysis
