Simple deprotection of acetal type protecting groups under neutral conditions

Chiral Brønsted Acid Catalyzed Cascade Alcohol Deprotection and Enantioselective Cyclization

The protection-deprotection sequence is vital to organic synthesis. Here, we describe a novel catalytic cascade where a chiral Brønsted acid selectively removes ether protecting groups and catalyzes intramolecular cyclization in one pot. We tested three model substrates from our previous work and investigated the rate of deprotection through gas chromatography (GC) studies. This work builds on our stereoselective synthesis of lactones by streamlining our synthesis. It also opens the door for additional investigations into other catalytic cascade reactions using chiral Brønsted acid catalysts.

Synthesis of Enantiopure C2-Symmetric Anthracenophane and Dimerization En Route to Multiple-Bridged Cyclophanes

We report the stereocontrolled synthesis of enantiopure C₂-symmetric anthracenophanes and their derivatization to D₂-symmetric multiple-bridged cyclophanes via photoinduced [4 + 4] dimerization.

First stereoselective total synthesis of FD-594 aglycon

Stereocontrolled access to the hexacyclic core of FD-594 has been achieved. The key steps include the intramolecular S(N)Ar reaction for construction of the densely functionalized xanthone skeleton, the stereoselective lactone cleavage using a chiral nucleophile to induce the axial stereochemistry, and the SmI(2)-mediated pinacol cyclization for the stereocontrolled conversion of axially chiral biaryl dialdehyde into the corresponding trans diol.