Question

CHEM 008L Lab 8: Diene Halogenations Purpose: In this virtual experiment, you will be investigating the effect of temperature on the addition of hydrochloric acid to 1,3-butadiene. You will be comparing key signals in the 13C NMR spectra of the reactant and product. HCI ci and/or 1,3-butadiene 3-chloro-1-butene 1-chloro-2-butene Figure 8.1 The addition of hydrochloric acid to 1,3-butadiene. Introduction: The 1,3-butadiene (AKA buta-1,3-diene) starting material is a conjugated diene, meaning that the double bonds are separated by only one single bond. When conjugated dienes react with one equivalent of an electrophile, such as HCl, there are two possible addition products that can form. One possibility is that the hydrogen and chlorine can add to adjacent carbons in what is known as a 1,2-addition to form the 3-chloro-1-butene product. Another possibility is that the hydrogen adds to one end of the conjugated system and the chlorine adds to the other end in what is known as a 1,4-addition to form the 1-chloro-2-butene product. The numbers 1,2 and 1,4 refer to the carbons of the conjugated system. CH=CH-CH=CH- B