This invention relates to a process for preparing (±)-2-exo-(2-Methylbenzyloxy)-1 -methyl-4-iso- propyl-7-oxabicyclo[2.2.1]heptane of the formula (I), (I) any one of its individual enantiomers or any non-racemic mixture thereof comprising the steps of (a) deprotonating (±)-2-exo-hydroxy-1 -methyl-4-isopropyl-7-oxabicyclo[2.2.1]heptane of the formula (II), (II) any one of its individual enantiomers or any non-racemic mixture thereof in the presence of at least one base of the formula [Mm+]n [An-]m (III) wherein Mm+ represents a m-valent metal cation wherein m is an integer of 1 or 2, and An_ represents a n-valent anion wherein n is an integer of 1 or 2, said base being capable of forming a solvent S1 selected from water, a C1-C4 alkyl alcohol or any combination thereof under the reaction conditions, to form a metal alkoxide or metal alkoxide solvate of the formula (IV), (IV) any one of its individual enantiomers or any non-racemic mixture thereof wherein Mm+, m and the solvent S1 have the same meaning as defined for the base of formula (III), and x denotes a number from 0 to 10, and (b) reacting the metal alkoxide or metal alkoxide solvate of the formula (IV), any of its individual enantiomers or any non-racemic mixture thereof with a 2-Methylbenzyl compound of the formula (V), (V) wherein X is a leaving group, wherein the steps (a) and (b) are conducted in the presence of at least one inert organic solvent S2 and comprise a further step of (c) simultaneously removing the solvent S1 from the reaction mixture.
该发明涉及一种制备(±)-2-外消旋-(2-甲基苄氧基)-1-甲基-4-异丙基-7-氧杂
双环[2.2.1]庚烷的方法,其
化学式为(I),其中(I)表示它的任一单对映体或任何非对映混合物,包括以下步骤:(a)在式(II)中存在至少一种碱的情况下去质子化(±)-2-外消旋-羟基-1-甲基-4-异丙基-7-氧杂
双环[2.2.1]庚烷,其中(II)表示它的任一单对映体或任何非对映混合物,其中碱的
化学式为[Mm+]n[An-]m(III),其中Mm+表示m价
金属阳离子,m为1或2的整数,An-表示n价阴离子,n为1或2的整数,所述碱能够在反应条件下形成溶剂S1,所述溶剂S1选择自
水、C1-C4烷基醇或它们的任何组合,以形成
化学式(IV)的
金属烷氧化物或
金属烷氧化物溶剂,其中(IV)表示它的任一单对映体或任何非对映混合物,其中Mm+、m和溶剂S1的含义与
化学式(III)中基的定义相同,x表示0到10之间的数,(b)将
化学式(IV)的
金属烷氧化物或
金属烷氧化物溶剂、它的任一单对映体或任何非对映混合物与
化学式(V)的2-甲基苄基化合物反应,其中(V)中的X是一个离去基团,步骤(a)和(b)在至少一种惰性有机溶剂S2的存在下进行,并包括进一步的步骤(c),即同时从反应混合物中去除溶剂S1。