Synthesis of a Peripherally Extended Triptycyl Group as an Aliphatic Steric Protection Group and Its Application to the Kinetic Stabilization of an Aliphatic Sulfenic Acid

Trp*, a novel triptycene (Trp)-based aliphatic steric protection group was synthesized, and its potential to offer kinetic stabilization by steric protection was evaluated in the context of synthesizing a sulfenic acid (RSOH), i.e., a highly reactive sulfur-containing species. The isolated sulfenic acid Trp*SOH is thermally very stable, which neatly demonstrates the steric protection provided by Trp*.