Design, Synthesis, and Reactivity of 1-Hydrazinodienes for Use in Organic Synthesis

A new 1-hydrazinodiene (1) has been developed and utilized in Lewis acid catalyzed, intermolecular Diels−Alder reactions with various electron-deficient alkenes. The hydrazine can then be deprotected, and a molecule of methanesulfinic acid is eliminated to provide a putative diazene intermediate (4), which then spontaneously undergoes a suprafacial 1,5-sigmatropic shift to yield stereochemically complex cyclohexenes. This method has been applied to the synthesis of a constitutionally and stereochemically complex decalin derivative.