New triene synthesis from sorbic acid: two-step synthesis of cis- and trans- galbanolenes
作者:Charles Fehr、José Galindo、Simone Chappuis
DOI:10.1016/s0040-4039(00)92216-0
日期:1992.4
The lithium dianion of sorbic acid reacts with hexanal at the C(2)-position to afford separable anti - and syn-hydroxy carboxylic acids 3 and 4 (87%; =59:41 or 79%; =16:84), whose stereospecific anti-decarboxylative elimination respectively affords (3E, 5Z)- and (3E, 5E)-1,3,5-undecatriene (1) and (2) (cis- and trans-galbanolenes (1 and (2) (69%). An alternative route to 1 involves conversion of 3
与己醛山梨酸发生反应的锂二价阴离子在C(2) -位置,得到可分离反-和顺式-羟基羧酸3和4(87%; = 59:41或79%; = 16:84),其立体定向抗脱羧消除分别提供(3 E,5 Z)-和(3 E,5 E)-1,3,5-十一碳三烯(1)和(2)(顺式和反式-加班烯(1和(2)(69%)。替代方法1涉及转化3、4至顺-内酯7(色谱后为45%),然后热合成-脱羧(81%)。所描述的方法是新的并且具有普遍适用性,如具有不同取代模式的三烯的合成所说明的。