Reactivity and degradation
"LSD," writes the chemist Alexander Shulgin, "is an unusually fragile molecule ... As a salt, in water, cold, and free from air and light exposure, it is stable indefinitely."[71]
LSD has two labile protons at the tertiary stereogenic C5 and C8 positions, rendering these centres prone to epimerisation. The C8 proton is more labile due to the electron-withdrawing carboxamide attachment, but removal of the chiral proton at the C5 position (which was once also an alpha proton of the parent molecule tryptophan) is assisted by the inductively withdrawing nitrogen and pi electron delocalisation with the indole ring.[citation needed]
LSD also has enamine-type reactivity because of the electron-donating effects of the indole ring. Because of this, chlorine destroys LSD molecules on contact; even though chlorinated tap water contains only a slight amount of chlorine, the small quantity of compound typical to an LSD solution will likely be eliminated when dissolved in tap water.[71] The double bond between the 8-position and the aromatic ring, being conjugated with the indole ring, is susceptible to nucleophilic attacks by water or alcohol, especially in the presence of light. LSD often converts to "lumi-LSD," which is inactive in human beings.[71]