Electrophilic substitution in naphthalenes: cyclisation of naphthylbutanols to tetrahydrophenanthrene
作者:Anthony H. Jackson、Patrick V. R. Shannon、Paul W. Taylor
DOI:10.1039/p29810000286
日期:——
Both 4-(1-naphthyl)butanol and 4-(2-naphthyl)butanol cyclised in refluxing boron trifluoride–ether to give 1,2,3,4-tetrahydrophenanthrene. By use of the corresponding, 1,1-dideuteriobutanol derivatives and analysis of the products by 220 MHz 1H n.m.r. spectroscopy it has been demonstrated that the 1-naphthylbutanol cyclises by two distinct pathways, (a) by direct attack (84%) at the 2-position, and
4-(1-萘基)丁醇和4-(2-萘基)丁醇均在回流的三氟化硼-醚中环化,得到1,2,3,4-四氢菲。通过使用相应的1,1-二氘代叔丁醇衍生物并通过220 MHz 1 H nmr光谱分析产物,已证明1-萘丁醇环化有两种不同的途径,(a)通过直接攻击(84%)在在第2位,以及(b)在萘核的1位通过ipso攻击(16%),然后进行重排。2-萘基丁醇仅通过在1-位上的直接取代而环化。另一方面,使用4-(4-甲氧基-1-萘基)-1,1-二氘代丁醇,ipso取代的比例上升到71%,如360 MHz所示1所得四氢菲混合物的H nmr光谱。