More specifically, the nimbin class of limonoids (2), isolated from the neem tree (Azadirachta indica), have been thoroughly investigated for their biological properties. The nimbin family is typified by a highly oxidized trans-decalin core bearing an equatorially disposed carboxylic ester derivative at C4, a fused tetrahydrofuran (THF) ring, and an oxidatively sensitive furan motif. These structural features have rendered nimbin-type limonoids attractive targets of total synthesis that have only recently fallen to synthetic efforts.