t-Butyl 4-alkyl-1H-pyrrole-2-carboxylates were oxidized with DDQ in the presence of MeOH at the α-position of the alkyl substituent at the C-4 position regioselectively to afford 4-acylpyrrole derivatives. On the other hand, treatment of the pyrroles with DDQ in the presence of AcOH furnished the corresponding 4-(1-acetoxyalkyl)pyrroles. The resulting 4-(acetoxymethyl)pyrrole reacted with various nucleophiles to afford the functionalized pyrrole derivatives in good yields.

Doubly locked 5Za15Ea-biliverdin (BV) derivative was synthesized toward the investigation of stereochemistry and function of the Pfr-form chromophore in bacteriophytochromes. A convergent synthetic method was established for the locked E-anti dipyrrole component with a 7-membered ring.

No abstract

-t-ButylIn order to synthesize different types of locked chromophores, it was necessary to prepare various pyrrole and pyrrolinone derivatives bearing a wide variety of functional groups. Herein we describe an oxidation of t-butyl pyrrole-2-carboxylates with o-chloranil and its application toward the synthesis of various types of functionalized pyrrolinone derivatives.

The metal‐free oxidation of title compounds (I) and (IV) in the presence of glycols proceeds smoothly and regioselectively to yield the corresponding pyrrole‐2,4‐dicarboxylates directly.