De novo synthesis of possible candidates for the Inagami–Tamura endogenous digitalis-like factor (EDLF) was achieved to validate a previously proposed structure. Our synthetic approach involves a highly regio- and diastereoselective Mizoroki–Heck reaction and a Friedel–Crafts-type cyclodehydration to construct steroidal tetracycle 14 as a versatile common intermediate leading to seven 2,14β-dihydroxyestradiol analogues 1a–c, 2a–c, and 3 as possible candidates. By comparing the potency of inhibitory activity against Na+/K+-ATPase between the synthesized candidates and the EDLF, it was found that the proposed structure is not likely to be a true structure of the Inagami–Tamura EDLF.

We describe a cascade Wacker/allylation sequence of β-hydroxy ynones by directly using simple allylic alcohols. This palladium(II)-catalyzed reaction occurs under mild conditions (0 °C to room temperature) and provides a new and efficient synthetic method for the preparation of allylated dihydropyrones. The regiochemical outcomes are consistent with a reaction pathway that includes an insertion/β-OH elimination sequence to form the allylic moiety. A remarkable changeover from allyl to formylethyl products occurs under the simple action of LiBr.Topics: Carbonyl compounds (organic); Catalysts; Elimination reaction; Elimination reaction; Heck reaction; Insertion reaction; Insertion reaction; Redox reaction; Redox reaction;

Diastereoselective synthesis of 3,3-disubstituted oxindoles has been examined by transformations involving nucleophilic addition, alkylation, and cycloaddition using chiral racemic N-aryl oxindoles bearing C–N axial chirality. The most striking features of this approach are high diastereoselectivities (up to >95:<5) when using ortho-monosubstituted N-aryl oxindoles and easy removal of the p-(benzyloxy)aryl moiety in the axially twisted amides by a mild two-step sequence.