Stereocontrolled Synthesis of (+)-Plagiogyrin A

Plagiogyrin
A (1) was first isolated from the fronds
of Plagiogyria matsumureana. Structurally, it features
an α-ketoaldehyde functional group in its hemiacetal form, fused
in a cis-substituted lactone ring. We have successfully
synthesized the skeleton of this natural product by employing a stereocontrolled
aldol reaction followed by the installation of the α-ketoaldehyde
moiety derived from the mild oxidation of an α-diazoketone.
Finally, anhydrous acidic conditions released the protected diol and
provided the required cyclized hemiacetal.