In conclusion, the total synthesis of przewalskin B was
accomplished using commercially available 2-cyclohexenone.
The key steps in the synthesis procedure included Diels-Alder
and Wolf-Kishner reactions to install the A ring, Claisen-
Johnson rearrangement to establish the spiro-quaternary center,
and RCM of a sterically crowded system to construct the cyclic
enone moiety. The asymmetric synthesis of przewalskin B,
which could be approached via an enantioselective Diels-Alder
reaction20 of diene 7 and methylacrolein, is in progress and will
be reported in due course.