Novel Thiophene Compound and Process for Producing Caffenofuran or Analogue Thereof from the Same

Abstract

The present invention provides a novel thiophene compound as a synthetic intermediate that is useful for efficient production of kahweofuran or an analogue thereof. The present invention also provides a process for producing kahweofuran or an analogue thereof using the novel thiophene compound as an intermediate material. Of novel thiophene compounds represented by Formula (1): wherein R1 is a hydrogen atom or a C1-C4 lower alkyl group; R2 is a hydrogen atom or an alcohol-protecting group; R3 is a hydrogen atom, —COR4 or —C(OH)R5 (wherein R4 and R5 each represent a C1-C4 lower alkyl group); provided that when R2 and R3 are hydrogen atoms, R1 is not any of a hydrogen atom, methyl group, or n-propyl group; a thiophene compound represented by Formula (2) is reduced and cyclized in the presence of a transition metal catalyst to produce kahweofuran or kahweofuran analogue (3a) shown below: wherein R1 is a hydrogen atom or a C1-C4 lower alkyl group, and R4 is a C1-C4 lower alkyl group.

Dependencies are inferred from the claim text.