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.
                            本发明提供了一种新型
噻吩化合物作为合成中间体,可用于高效生产加氢
呋喃或其类似物。本发明还提供了一种以该新型
噻吩化合物为中间体材料生产加氢
呋喃或其类似物的工艺。
式(1)所代表的新型
噻吩化合物:
其中 R1 是氢原子或 C1-C4 低级烷基;R2 是氢原子或醇保护基;R3 是氢原子、-COR4 或-C(OH)R5(其中 R4 和 R5 各自代表 C1-C4 低级烷基);当 R2 和 R3 为氢原子时,R1 不是氢原子、甲基或正丙基中的任何一个; 式(2)代表的
噻吩化合物在过渡
金属催化剂存在下被还原和环化,生成下图所示的卡 韦
呋喃或卡韦
呋喃类似物(3a):
其中 R1 是氢原子或 C1-C4 低级烷基,R4 是 C1-C4 低级烷基。