Stereoselective Total Synthesis of Passifloricin A

The stereoselective total synthesis of passifloricin A ( 1 ), a naturally occurring dihydropyranone with leishmanicidal and antiprotozoal activities, has been accomplished starting from protected glyceraldehyde using Maruoka asymmetric allylation, diastereoselective iodo‐carbonate cyclization, and Grubbs' olefin metathesis reactions as the key steps.     

A Ni2+ selective chemosensor based on partial cone conformation of calix[4]arene

Synthetic strategies are described to synthesize the calix[4]arene diamine 4 of partial cone (paco) conformation, which on condensation with 9-anthracene carbaldehyde forms the chemosensor 5 in paco conformation. The chemosensor 5 undergoes fluorescence enhancement in the presence of Ni(2+) ions.