(diphenylphospino)lithium (=lithium diphenylphosphanide) in THF at 0° (Scheme 4). However, the purification of 4a/4b was very difficult since these bis‐phosphines decomposed on column chromatography on silica gel and were converted mostly by oxidation by air to bis(phosphine oxides) 5a and 5b. Both 5a and 5b were also obtained in pure form by reaction of 3a or 3b with (diphenylphosphinyl)lithium (=lithium oxidodiphenylphospanide)
在THF中用
二异丁基氢化铝(D
IBAH)还原庚烯二酯1得到了庚烯1,2-二
甲醇2a和其双键移位(
DBS)异构体2b的混合物(方案3)。两种产物都可以通过
硅胶柱色谱法分离。随后在CH 2 Cl 2中用PCl 5对2a或2b进行
氯化,得到了1,2-双(
氯甲基)庚二烯3a及其
DBS异构体3b的混合物。长时间色谱分离后,产物3a和3b以纯净形式获得。它们在低温下从己烷/ Et 2 O 7:1平稳结晶,其结构通过X射线晶体结构分析确定(图1和2)。在0°下用THF中过量的(
二苯基膦基)
锂(=
二苯基膦酸锂)容易地通过
二苯基膦基进行3a或3b的Cl取代基的亲核交换(方案4)。但是,4a / 4b的纯化非常困难,因为这些
双膦在
硅胶柱色谱上分解并且大部分被空气氧化转化为双(氧化膦)5a和4b。5b。两个图5a和图5b也以纯的形式获得通过的反应图3a或3b中与(
二苯基膦基)
锂(=
锂oxidodiphenylp