Synthesis of a New 2,3-Diaminoconduritol with Conduritol F Structure

A new 2,3‐diaminoconduritol derivative with the conduritol F structure was prepared starting from cyclohexa‐1,4‐diene. Initially, a lactam, prepared by the cycloaddition of chlorosulfonyl isocyanate (CSI) to cyclohexa‐1,4‐diene, was converted into an amino acid. The conversion of the acid functionality into an isocyanate resulted in the formation of an imidazolidinone derivative, formed by an intramolecular cyclization. In the second part of this work, the known anhydride, 3a,4,7,7a‐tetrahydroisobenzofuran‐1,3‐dione was successfully converted into the desired bis(carbamate). The bromination of the double bond in the six‐membered ring followed by a DBU‐induced (DBU = 1,8‐diazabicyclo[5.4.0]undec‐7‐ene) HBr elimination furnished the symmetrical diene. The photooxygenation of the diene unit afforded the bicyclic endoperoxide. The reaction of the endoperoxide with thiourea followed by acetylation resulted in the formation of a syn‐configured diacetate. The deprotection of the urethane and acetate groups gave the new 2,3‐diaminoconduritol with the conduritol F structure. A new 2,3‐diaminoconduritol with the conduritol F structure was prepared starting from the known anhydride 3a,4,7,7a‐tetrahydroisobenzofuran‐1,3‐dione, which was successfully converted into the desired diene with bis(carbamate) functional groups. The photooxygenation of the diene followed by cleavage of the peroxide linkage and removal of the protecting groups gave the new 2,3‐diaminoconduritol.