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A J Birch

Publications and source records attributed to A J Birch.

15 recordsLinked to original sources

Steroid hormones and the Luftwaffe. A venture into fundamental strategic research and some of its consequences: the Birch reduction becomes a birth reduction.

I recount my involvement in the development of biologically active, totally synthetic steroid hormones since 1941. The reasons for my approach to the first total synthesis of a potent androgen are given. I touch on the even more important general synthetic outcomes from ideas generated by the search for useful amounts of a cortically active hormone, such as novel angular methylations, partial hydrogenations of aromatic systems (Birch reductions), and novel usages in synthesis based on the unique structures so generated. The Birch process was critical for synthesis of the first oral contraceptives. A need to explain the structures of Birch reduction products and the experimental requirements resulted in further elucidations of the mechanism of reduction processes, notably for aromatic compounds. The first theoretical and practical distinction between structures of products as determined by a reaction rate or an equilibrium position was first exploited experimentally in the deconjugation of cholest-4-en-3-one in the final step of the first facile total synthesis of cholesterol. A knowledge gained of the biosynthesis of steroids and its specific enzymes helped to initiate my general polyketide theory of biosynthesis and also my idea of outdoing enzyme achievements with organometallic complexes ("inorganic enzyme chemistry"). I assert the high historic importance of steroids in promoting the advance of general organic chemistry within many fields.

Adrenal Cortex Hormones

Biosynthesis in theory and practice: structure determinations.

Classical appraoches to structure determinations of natural molecules can be assisted by biosynthetic considerations. Application of these needs some structural evidence, based on degradations and spectra, as to biogenetic type. This evidence can be effectively supplemented by incorporations of precursors labelled with 14C, 13C or 15N, as appropriate, with examinations of the distributions of label in the product. Several examples of both classical and incorporation techniques are reviewed.

Alkaloids