Egbert Havinga

“I am inclined to believe that there is no end to the evolution of science and the study of organic chemistry in particular” -Egbert Havinga

May 7 1909 - November 22 1988

Egbert Havinga received his academic education at Utrecht University, the Netherlands, where he specialised in organic chemistry (with F. Kögl) and theoretical physics (with H.A. Kramers).

In 1939 he completed his Ph.D. studies under the guidance of Kögl with a thesis on: "Monomolecular Layers: Structure and Chemical Reactions". In 1946, after having served at the Veterinary Faculty at Utrecht University (Laboratory of Medicinal Chemistry) he became full professor of Organic Chemistry and director of the Laboratory of Organic Chemistry at Leiden University. He stayed there until his retirement from the Chair in 1979.

Havinga's scientific interest was very broad. He worked in many different areas of organic chemistry ranging from physical organic to bio-organic. Widely recognised are his contributions to vitamin D chemistry (pathways and products of thermal and photochemical isomerisations), stereochemistry (spontaneous formation of chiral substances, conformational analysis of non-aromatic 5 and 6 membered ring compounds) and peptide and enzyme chemistry (structure/activity relationships in angiotensin and ribonuclease analogues).

Among his photochemical researches his work on the photo-reactivity of vitamin D and its isomers and of conjugated trienes, and on aromatic photo-substitution probably had the widest impact. The latter type of reaction was discovered in Leiden.

In both fields he was the first to call attention to the remarkable opposite (stereo)specificity of photo-induced and thermal reactions. In the vitamin D field this discovery inspired to the first hint on the importance of orbital symmetry in the control of these reactions. A further factor of importance in determining the course of photo-reactions of conjugated trienes was recognised in the ground state conformation, to be expressed later in the principle of Non-Equilibration of Excited Rotamers (NEER).

In the field of aromatic photo-substitution detailed and sophisticated studies led to the unravelling of the mechanisms in the conspicuous diversity of reaction courses and to a general classification of the distinct categories of aromatic photo-substitution within a unifying mechanistic framework.

Some shorter lines of Havinga's research concerned the transmission of substituent effects in styrenes and stilbenes, the occurrence of tautomerism, dimerisation and E/Z isomerisation in aromatic nitroso compounds, various aspects of surface chemistry and of plant growth regulation, and covalent catalysis. Many of these investigations were undertaken out of curiosity for the factors that control the exemplary efficiency of enzymatic reactions.

Apart from its broadness and versatility Havinga's research is characterised by the early introduction of physical methods into organic chemistry. In his papers one notes the use of advanced spectroscopic techniques and of quantum mechanical calculations already at a time when it was far from commonplace.

The number of Ph.D theses prepared under the guidance of Havinga amounts to 166. For many students a decisive role in choosing to study organic chemistry with Havinga was played by his lecture courses. Professor Havinga was an outstanding teacher of organic chemistry on all its levels. His advanced courses on the chemistry of natural products were particularly popular and attracted numerous students, also from non-chemical disciplines who attended, not with a future examination in mind, but just for the fun of being inspired by someone who loves his subject and can convey his enthusiasm. Havinga spent much time in preparing his lectures and planned them meticulously and in very great detail.

Havinga was elected as a member of the Royal Netherlands Academy of Arts and Sciences in 1956, and as an honorary member of the Royal Netherlands Chemical Society in 1978. In 1968 he was knighted Ridder in de Orde van de Nederlandse Leeuw. He received several Awards, Medals and Foreign Memberships.

Egbert Havinga has been the author or coauthor of well over 250 research papers. A personal retrospective view of his academic career is to be found in: Havinga, E., Enjoying Organic Chemistry, 1927-1987; (Profiles, Pathways, and Dreams: Autobiographies of Eminent Chemists; J.I. Seeman, Series Ed.), American Chemical Society, Washington, DC, 1991 (2nd printing 1992).

Leading references to his main areas of research are:

Aromatic Photosubstitution:

Havinga, E., Chimia 1962, 16, 145.
Havinga, E.; Kronenberg, M.E., Pure Appl. Chem. 1968, 16, 137.
Cornelisse, J.; De Gunst, G.P.; Havinga, E., Adv. Phys. Org. Chem. 1975, 11, 225.
Cornelisse, J.; Havinga, E., Chem. Rev. 1975, 75, 353.
Cornelisse, J.; Lodder, G.; Havinga, E., Rev. Chem. Intermed. 1979, 2, 231.
Den Heijer, J.; Shadid, O.B.; Cornelisse, J.; Havinga, E., Tetrahedron 1977, 33, 779 and preceding papers in this series.

Conformational Analysis:

Romers, C.; Altona, C.; Buys, H.R.; Havinga, E., In Topics in Stereochemistry; Eliel, E.L., Allinger, N.L., Eds.; Wiley: New York, 1969; Vol. 4, p 39.
Buys, H.R.; Leeuwestein, C.H.; Havinga, E., Tetrahedron 1970, 26, 845 and preceding papers in this series.

Vitamin D Conjugated Trienes:

Havinga, E.; De Kock, R.J.; Rappoldt, M.P., Tetrahedron 1960, 11, 276.
Havinga, E.; Schlatmann, J.L.M.A., Tetrahedron 1961, 16, 146.
Havinga, E., Chimia 1962, 16, 145.
Sanders, G.M.; Pot, J.; Havinga, E., Fortschr. Chem. Org. Naturst. 1969, 27, 131.
Havinga, E., Experientia 1973, 29, 1181.
Jacobs, H.J.C.; Havinga, E., Adv. Photochem. 1979, 11, 305.
P.A. Maessen, P.A.; Jacobs, H.J.C.; Cornelisse, J.; Havinga, E., Angew. Chem. Int. Ed. Engl. 1983, 22, 718, and preceding papers in this series.

Studies on Polypeptides:

Serdijn, J.; Bloemhoff, W.; Kerling, K.E.T.; Havinga, E., Recl. Trav. Chim. PaysBas 1984, 103, 351 and preceding papers in this series.