Organska kemija doživjela je tijekom proteklog stoljeća duboke i korjenite promjene kojima je Vladimir Prelog bio svjedokom i aktivnim sudionikom. Sintetska kemija i istraživanja strukture prirodnih spojeva bile su u središtu interesa organskih kemičara. Preparativne metode omogućile su pripremu mnogih novih spojeva. Sveučilišni laboratoriji bili su u sprezi s industrijskim pogonima, gdje je prednjačila njemačka kemijska industrija. Sve se to do sredine 20. stoljeća zbivalo na empirijski stečenim saznanjima tako da je organska kemija bila praktički odvojena od drugih kemijskih područja. U takvom se ozračju školovao Vlado Prelog u Pragu, kao učenik Emila Votočeka i svog neposrednog mentora Rudolfa Lukeša. Praksu u sintezi organskih spojeva stekao je pripravljajući naručene kemikalije u malom pogonu svog poslodavca i prvog doktoranda G. J. Drize. Kad je Lukeš intuitivno predložio strukturu adamantana, Prelogu je sinteza tog visokosimetričnog spoja predstavljala izazov koji je ostvario njegov doktorand Rativoj Seiwerth. Povezanost s tvornicom "Kaštel" potaknula je njegov interes za kemiju biološki aktivnih spojeva, a jedinstvena stereokemija adamantana usmjerila je njegova istraživanja na stereokemiju i klasifikaciju kiralnih spojeva poznatu kao CIP-sustav. Ta su mu istraživanja osigurala Nobelovu nagradu, koju je 1975. dijelio s Johnom Cornforthom. Kao nasljednik Ružičke na Katedri za organsku kemiju Savezne visoke tehničke škole u Zürichu (ETH) prepoznao je važnost povezivanja klasične, tradicionalne organske kemije, koja se temeljila na dobroj memoriji i napornom radu u laboratoriju i modernog pristupa koji su u nastavu i istraživanja uveli anglosaksonski kemičari. Novo razdoblje za organsku kemiju počinje sredinom 60-ih godina kad su Woodward i Hoffmann objavili pravila orbitalne simetrije. Primjena kvantno-mehaničkog pristupa i nagli procvat pouzdanih računalnih metoda kao i novih analitičkih tehnika, omogućili su rješavanje mnogih problema odnosa strukture i reaktivnosti kao i sinteze kompleksnih prirodnih spojeva, što je ranije bilo nedostupno primjenom klasičnih metoda. Prelog je premostio jaz koji je dijelio tradicionalnu i modernu školu organske kemije, što je dovelo do toga da su gotovo nestale bitne razlike između analitičke, fizikalne i organske kemije. Istraživanje prirodnih spojeva i njihove uloge u biološkim procesima danas proučava molekularna biologija i Prelogovi su posljednji radovi bili posvećeni upravo bio-organskoj kemiji. I nakon odlaska u mirovinu 1975. god., Prelog je kao "izvanredni student" u svojoj grupi okupio nekoliko vrsnih zagrebačkih kemičara čiji je boravak u Zürichu pokrivao vlastitim sredstvima. Vladimir Prelog ući će u povijest kemije kao najveći organski kemičar 20. stoljeća., Organic chemistry in the past century has undergone several profound changes and Vlado Prelog, as the great organic chemist of our time, was actively involved in these changes. During the first half of the 20th century, synthesis of new organic compounds and the investigation of natural compounds were in the centre of interest of contemporary organic chemists. New methods enabled the preparation of new compounds such as numerous drugs and dyes, thus eliminating in some cases the tedious isolation from natural sources. The German chemical industry rapidly expanded and some small enterprises specialized in the preparation of tailored compounds for use in academic research. Until the first half of the last century, organic chemistry was based on empirical knowledge and meticulous and hard work in the laboratory, and it was practically separated from other branches of chemistry. In Prag, Prelog studied chemistry under the guidance of Emil Votoček, and his few years older mentor and friend Rudolf Lukeš. He practiced preparative organic chemistry in a small commercial outfit of G. J. Driza, who become his first doctoral student. He witnessed the structure of adamantane intuitively suggested by Lukeš, which by its highly symmetrical structure, fascinated Prelog and raised his interest in stereochemistry and the possible synthesis of adamantane. This remained a challenge for him in the years to come, to be solved in 1941 by his student and successor Rativoj Seiwerth at the very end of his stay as professor of organic chemistry at the University of Zagreb. Establishing collaboration with Kaštel, the leading pharmaceutical factory in Zagreb, had secured him the financial support needed for his research in Zagreb. From the stereochemistry of adamantane to the formulation of the CIP classification of chirality and the awarding of the Nobel Prize jointly with John Cornforth in 1975, Prelogs life was devoted to the study of the structure and stereochemistry of many biologically active organic compounds. A fascinating teacher and charismatic person, his career was associated with the ETH which became the mecca of organic chemistry in the past century. Following the tradition of RuŢička, whose successor as chair of organic chemistry at ETH he became in 1957, Prelog recognized the importance of the emerging new branch of organic chemistry practiced in the U.S. which centered on reaction mechanisms, and thus bridged the gap between traditional and modern organic chemistry. He later became increasingly interested in bioorganic chemistry, but never lost contact with chemistry and his colleagues in Zagreb. After his retirement, he invited and provided support to younger chemists from "Pliva" who temporarily joined his group in Zürich. Vladimir Prelog, who died in 1998, entered the hall of fame as one of the greatest organic chemists of the 20th century.