Regioselective deprotonation of 3-chloro-1-tosylpyrrole is used to prepare the 2-formyl derivative. Application of this chemistry in a synthesis of the left hand pyrrolo-furan substructure of roseophilin is described.
The title synthesis was accomplished starting with 3-chloro-2-formylpyrrole. The synthetic scheme featured one-pot preparation of the 4-methoxy-2-(pyrrol-2-yl)furan from the 2-acetoacetyl-pyrrole and coupling reactions of the C-5-position of the 4-methoxy-2-(pyrrol-2-yl)furan with various types of aldehydes and ketones as key steps.
Mild Friedel–Crafts Reactions Enable a Robust Synthesis of Roseophilin
An 11-step total synthesis of either enantiomer of roseophilin has been developed. The chemistry features effective production of a challenging carbocation on a macrocyclic segment 25 and a highly efficient intermolecular Friedel–Crafts alkylation reaction to integrate a complex furan-pyrrole unit 5 regioselectively with this carbocation under very mild reaction conditions.
Regioselective deprotonation of 3-chloro-1-tosylpyrrole is used to prepare the 2-formyl derivative. Application of this chemistry in a synthesis of the left hand pyrrolo-furan substructure of roseophilin is described.