Stereoselective total synthesis of natural (S)-bakuchiol and its enantiomer

Article abstract of DOI:10.1002/hlca.200890041

A practical stereoselective synthesis of (S)-bakuchiol (1) and its enantiomer is reported. The important intermediate, (R)-configured β-siloxy aldehyde 5, was obtained in three steps from the easily available material geraniol (2) via the key step of Yamamoto's rearrangement of epoxy silyl ethers. (S)-Bakuchiol (1) and its enantiomer, (R)-bakuchiol (17), were finally obtained in different synthetic sequences with overall yields of 51% (ten steps) and 40% (nine steps) from geraniol (2), respectively.