Revised structure of γ-lactone polyketide from Diaporthe sp. SXZ-19 and its C8-epimer
were synthesized from TBS protected (S)-lactaldehyde and 2,3-O-cyclohexylidene-d-glyceraldehyde, which was derived from d-mannitol. The target γ-lactones were prepared via a common alkyne intermediate utilizing
alkyne-aldehyde coupling reactions by changing the reaction conditions. In addition,
Carreira and Ohira–Bestmann reactions were used as key steps to achieve the targets.
Key words
natural product - C8-epimer -
d-mannitol - Carreira reaction - Ohira–Bestmann reaction