jo049426c_si_001.pdf (3.91 MB)
Studies on the Synthesis of Landomycin A. Synthesis of the Originally Assigned Structure of the Aglycone, Landomycinone, and Revision of Structure
journal contribution
posted on 2004-07-23, 00:00 authored by William R. Roush, R. Jeffrey NeitzThe originally proposed structure (2) of landomycinone, the aglycone of landomycin A, has been
synthesized and shown to be nonidentical to the naturally derived landomycin A aglycone. The
synthesis of 2 features the Dötz benzannulation reaction of chromium carbene 5 and alkyne 6, and
the intramolecular Michael-type cyclization reaction of the phenolic naphthoquinone 20. It is
proposed that natural landomycinone possesses the alternative structure 3, but attempts to access
this structure via the Michael-type cyclization of the isomeric phenolic naphthoquinone 38 have
been unsuccessful.