Concise Total Synthesis of Trichodermamides A, B, and C Enabled by an Efficient Construction of the 1,2-Oxazadecaline Core

We
report herein a facile and efficient method of the construction
of the cis-1,2-oxazadecaline system, distinctive
of (pre)­trichodermamides, aspergillazine A, gliovirin, and FA-2097.
The formation of the 1,2-oxazadecaline core was accomplished by a
1,2-addition of an αC-lithiated O-silyl ethyl pyruvate oxime to benzoquinone, which is followed by
an oxa-Michael ring-closure. The method was successfully applied to
the concise total synthesis of trichodermamide A (in gram quantities)
and trichodermamide B, as well as the first synthesis of trichodermamide
C.