First total synthesis of (±)-13-hydroxyneocembrene

Article abstract of DOI:10.1002/jccs.199900082

First total synthesis of (±)-13-hydroxyneocembrene (1), starting from 6-methyl-5-hepten-2-one (6) and geraniol (7), is described. The key steps are (i) the addition of sulfur-stabilized carbanion 12 to aldehyde 9, (ii) the synthesis of 18 by using phase-transfer catalyzed coupling reaction, and (iii) low-valent titanium-induced intramolecular coupling of oxo aldehyde 3 to afford the target molecule after the final deprotection.