NOVEL THIOPHENE COMPOUND AND PROCESS FOR PRODUCING CAFFENOFURAN OR ANALOGUE THEREOF FROM THE SAME

摘要

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 R 1 is a hydrogen atom or a C 1 -C 4 lower alkyl group; R 2 is a hydrogen atom or an alcohol-protecting group; R 3 is a hydrogen atom, -COR 4 or -C(OH)R 5 (wherein R 4 and R 5 each represent a C 1 -C 4 , lower alkyl group); provided that when R 2 and R 3 are hydrogen atoms, R 1 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 R 1 is a hydrogen atom or a C 1 -C 4 lower alkyl group, and R 4 is a C 1 -C 4 lower alkyl group.