Structure Confirmation of Dechlorotrichotoxin A through Stereoselective Total Synthesis

The stereoselective total synthesis of dechlorotrichotoxin
A, alongside
the synthesis of a 1:1 10E/Z mixture
of trichotoxin A, was successfully achieved, commencing from the natural
monoterpenoid (−)-citronellal. Key steps in the synthesis involved
introducing three alkenes and establishing a stereogenic secondary
alcohol center. These transformations were accomplished through olefin
cross-metathesis, Tebbe olefination, and enantioselective allylation
using a chiral phosphoric acid. A comparison of the spectroscopic
data between the synthetic dechlorotrichotoxin A and the reported
spectra confirmed that the polyketide isolated from a Smenospongia species corresponds to trichotoxin A rather than dechlorotrichotoxin
A.