Aleksander Mikhaylovich Zaytsev (), also spelled as Saytzeff and Saytzev (2 July 1841 – 1 September 1910), was a Russian chemist. He worked on organic compounds and proposed Zaitsev's rule, which predicts the product composition of an elimination reaction. Early years Zaytsev was born in Kazan. He was the son of a tea and sugar merchant, who had decided that his son should follow him into the mercantile trades. However, at the urging of his maternal uncle, Zaytsev was allowed to enroll at University of Kazan to study economics. At this time, Russia was experimenting with the cameral system, meaning that every student graduating in law and economics from a Russian university had to take two years of chemistry. Zaytsev was thus introduced to Aleksandr Mikhailovich Butlerov. Early on, Zaytsev began working with Butlerov, who clearly saw in him an excellent laboratory chemist, and whose later actions showed that he felt that Zaytsev was an asset to Russian organic chemistry. On the death of his father, Zaytsev took his diplom in 1862, and immediately went to western Europe to further his chemical studies, studying with Hermann Kolbe in Marburg, and with Charles Adolphe Wurtz in Paris. This went directly against the accepted norms of the day, which had the student complete the kandidat degree (today approximately equivalent to the doctor of philosophy degree, but then closer to the thesis for the B.Sc. (Hons.) degree in British universities), and then spend two or three years in study abroad (a komandirovka) before returning to Russia as a salaried laboratory assistant studying for the doctorate. During his studies with Kolbe between 1862 and 1864, Zaytsev discovered sulfoxides and trialkylsulfonium salts. In 1864, he moved to Paris, where he worked for a year in the laboratories of Wurtz before returning to Marburg in 1865. At this time, Kolbe accepted a call to Leipzig, and Zaytsev, now out of money, returned to Russia. Upon his return, Zaytsev again joined Butlerov as an unpaid assistant. During this time, he wrote a successful kandidat dissertation. Career In order to teach, he required either a master's degree from a Russian university, or a Ph.D. from a foreign university, so he wrote up his work on the sulfoxides and submitted it to the University of Leipzig where (probably thanks to Kolbe's influence) he was awarded the Ph.D. in 1866. With Zaytsev now holding the Ph.D., Butlerov was able to