Preparation, purification and cis-trans isomerization of 2-butene-1, 4-diol

The preparation of cis- and trans-2-butene-1,4-diol has been reported in chemical literature by numerous workers. A well established procedure to obtain the cis isomer is to hydrogenate 2-butyne-1,4-diol at two to four atmospheres pressure in the presence of catalysts, such as Raney nickel or colloidal palladium. This reduction is selective and can be stopped easily at the ethylenic stage. The reaction has been studied by Lozac\u27h who stated that the Raman spectrum of 2-butene-1,4-diol prepared in this way indicates the presence of the cis iomer only. Lozac\u27h does not mention the degree of purity of this product and nothing could be found about purity in other articles dealing with the preparation of cis-2-butene-1,4-diol. It is reasonable to believe that in the preparation of this compound under ordinary laboratory conditions small amounts of 2-butyne- and/or butane-1,4-diol may be present. The boiling points of these two are close to the boiling point of the olefin and it would be very difficult to separate the latter from the other two by distillation