Stereospecific total synthesis of dl-pentalenolactone

Application of Pauson–Khand reaction in the total synthesis of terpenes

“…Its stimulating properties and substantial chemical activity prompted Danishefsky et al to develop a fascinating total synthesis of 497 in 1978. [330][331][332] In 2012, Li and co-workers 332 reported a protocol 333,334 for the asymmetric total synthesis of methyl ester of pentalenolactone A 497 based on an intramolecular Pauson-Khand reaction. It began with aldehyde 493 which upon treatment with lithium ethynylate at À78 C afforded propargyl alcohol 483 in 95% yield.…”

Efficient Total Synthesis of Bioactive Natural Products: A Personal Record

“…Once again, the introduction of the TMS group provided the necessary driving force to initiate the Michael addition, which was successfully applied to the TIMO to give α‐methylene‐δ‐pentyrolactone 24 . A subsequent series of functional group interconversions, including methylation via the Stille coupling of an enol triflate, which occurred with inversion of the stereochemistry at C1, and epoxidation of the exocyclic methylene using the reduction–epoxidation–oxidation sequence reported by Danishefsky et al [26]. in their synthesis of compounds belonging to the pentalenolactone family, completed our total synthesis of pentalenolactone A methyl ester 26 .…”

The Total Synthesis of Quadrone

“…First, excellent access to compound V\ had been provided. Second, the feasibility of angular functionalization with formation of the eis fused bicyclo [3,3,0]octane system had been demonstrated [of. compound ^) .…”

“…Our laboratory was particularly attracted to this target since we were, at the time of the emergence of quadrone, struggling to complete the last phases of the total synthesis of pentalenolactone 2 (3,4), a structurally related sesquiterpene of reputed anti-tumor potential.…”