芸香科呋喃喹啉酮類生物鹼成分Acrophylline之合成研究

Studies on the Constituents of Furoquinolone Alkaloids in Rutaceae Synthetic Investigation of Acrophylline

謝博進(Borjinn Shieh) ； 林宗平(Tsung-Ping Lin)

《化學》 48卷4期 (1990/12) Pp. 259-264

https://doi.org/10.6623/chem.1990033

摘要

本研究以改良之Tuppy-Böhm法進行天然分離之呋喃喹啉酮類生物鹼Acrophylline之全合成，而以由3-methoxyaniline與ethyl 2-ethoxy-4-oxo-4,5-dihydrofuran-3-carboxylate反應得到之ethyl 2-(3'-methoxyanilino)-4-oxo-4,5-dihydrofuran-3-carboxyate (4)為起始原料。將化合物4加熱環化而得到產物5，隨後將化合物5在乙醇鹼存在下以硼氫化鈉還元可得基本母環化合物furo-quinolinone(6)，接著化合物6在DMF存在下進行isoprenylation而得兩個異構性產物7及1，經純化後由物理及光譜性質，吾等判斷合成之化合物1之Acrophylline與天然分離者有相同之組成。因此有關Acrophylline之結構為正確無誤，且由氧或氫上取代衍生物之苯環上C_5-H在^1H-NMR光譜上有明顯之差異，及^(13)C-NMR之C-4及N-CH_2-與O-CH_2-之差異可資辨別。

並列摘要

A synthetic approach to the naturally isolated alkaloid acrophylline has been carried out by the modified Tuppy-Böhm method. The synthesis starts with ethyl 2-(3'-methoxyanilino)-4-oxo-4,5- dihydrofuran-3-carboxyate(4) obtained from the condensation of readily availably 3-methoxyaniline and ethyl 2-ethoxy-4-oxo-4,5-dihydrofuran-3-carboxylate. Thermal cyclization of 4 gives 5 which is reduced with sodium borohydride to afford the corresponding furoquinolinone 6. Isoprenylation of 6 with DMF gives 1. Both physical and spectral properties suggest that the synthetic and natural acrophylline have the same structure. Here, we can distinguish the O-Allylated and N-Allylated compound by the difference of ^1H-NMR (at C_5-H) and ^(13)C-NMR at the N-CH_2- and O-CH_2- between the N- and O- Allylation compound.