posted on 2024-01-26, 21:44authored byTimothy
J. Fazekas, Glenn C. Micalizio
Asymmetric de novo construction of limonoids remains
a challenging
problem in stereoselective synthesis due to the diverse and complex
structures associated with this class of natural products. Here, a
unique synthetic pathway to an “intact” limonoid system
is described. The synthetic route is based on exploiting an oxidative
rearrangement reaction of a densely functionalized late-stage intermediate
to simultaneously establish the stereodefined C10 quaternary center
and an allylic acetate at C12. This is a unique example of a complex
rearrangement reaction that proceeds on a system whose presumed intermediate
allyl cation is highly hindered and lacks neighboring protons that
are otherwise required for cation termination.