4,4-Dimethyl-l-pentene

The 2,3-dimethyl-1-pentene formed in the dehydration reaction must be optically pure because it arises from optically pure alcohol by a reaction that does not involve any of the bonds to the stereo-genic center. When optically pure 2,3-dimethyl-l-pentene is hydrogenated, it must yield optically pure 2,3-dimethylpentane—again, no bonds to the stereogenic center are involved in this step. 

Because the alkane is 50% optically pure, the alkene fraction must have contained equal amounts of optically pure 2,3-dimethyl-l-pentene and its achiral isomer 2,3-dimethyl-2-pentene. 

Ni(acac)2-(C2H5)3Al2Cl3-PCy3 methylpentenes (36.9%), 2,3-dimethyl-l-pentene (60%), 2,3-dimethyl-2-butene (1.2%), 4-hexene (1.0%) 709... 

C2H5A1C1-H20) 2-pentene (13.2%), trans-4-methyl-2-pentene (15.2%), 2,3-dimethyl-l-pentene (43.1%), 2-methyl-l-pentene (13.3%), n-hexenes (3.3%) ... 

Catalytic hydrogenation of (S)-2,3-dimethyl-l-pentene gives only one optically active product. 

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