作者:Graham Carr、Christopher Dean、David Whittaker
DOI:10.1039/p29880000351
日期:——
A number of terpenoid bicyclic ethers have been prepared by cyclisation of suitable precursors in fluorosulphuric acid–sulphur dioxide. The products are formed under a mixture of thermodynamic and kinetic control, and five-, and six-, and seven-membered-ring ethers are obtained. Both primary and secondary alcohols have been cyclised by attack of the hydroxy group on carbocation centres generated by
通过将合适的前体在氟代硫酸-二氧化硫中环化,制备了许多萜类双环醚。在热力学和动力学控制的混合物下形成产物,并获得五元,六元和七元环醚。伯醇和仲醇均已通过烯烃的质子化或叔醇的电离产生的碳正离子中心上的羟基进攻而被环化。叔醇太容易离子化而无法提供醚性氧原子。不饱和仲醇二氢香芹酚(2)与五氟化锑在二氧化硫中的反应通过可能不涉及碳阳离子的反应得到醚,因此可能适合于由在酸中容易重排的底物形成醚。