Über aktivierte Ester, VII. Untersuchungen über die peptidchemische Verwendbarkeit von Acylaminosäure-chinolyl-(8)-estern

The life and work of Geoffrey Tyndale Young

Geoffrey Tyndale Young was born in England's Peak District in 1915: his father and both grandfathers were pharmaceutical chemists. He graduated from the Universities of Birmingham and Bristol and was a transatlantic scientific liaison officer in the Second World War, shortly after which he was elected to a Fellowship at Jesus College Oxford. He combined peptide synthesis research, undergraduate teaching, and College administration with leadership in European peptide science and was universally respected for his integrity, wisdom, and unflappable diplomacy. A close friend of Josef Rudinger, he attended almost all of the first two dozen European Peptide Symposia 1958-1996. When he retired in 1982, he was appointed an Officer of the Order of the British Empire and was elected an Emeritus Fellow of Jesus College, of which he had been Acting Principal 1973-1977. In retirement, he was instrumental in setting up this journal and steered the formation of the European Peptide Society, of which he was the first chairman. In 1950, he married Janet Mary Baker, later Baroness Young of Farnworth, Leader of the British House of Lords 1982-1983, who died in 2002: they had three daughters who survive him. He died at home in Oxford on 24 May 2014 aged 98.

Efficient microwave assisted access to chiral O-(alpha-protected-aminoacyl)steroids

Chiral O-(alpha-protected-aminoacyl)steroids 4a-f, 6a-b, 8 and 4a+4d and O-(alpha-protected-dipeptidoyl)steroids 12a,b are conveniently prepared under microwave irradiation in isolated yields of 65-96%, with complete chirality retention. The reaction utilized readily available N-(Z-alpha-aminoacyl)benzotriazoles 2a-f and Z-dipeptidoylbenzotriazole 11, with naturally occurring steroidal alcohols 3,5,7,9.

High yield synthesis of tentoxin, a cyclic tetrapeptide

Tentoxin is a naturally occurring phytotoxic cyclic tetrapeptide excreted by fungi of the Alternaria alternata family. The four total syntheses of tentoxin published to date give poor total yields, mainly owing to two difficulties, the introduction of the dehydro amino acid and more especially the cyclization step. Here we describe a method that stereospecifically introduces Z-dehydrophenylalanine (deltaZPhe) by a modified Erlenmeyer aldolization reaction. The linear tetrapeptide, Boc-R1Ala-Leu-R2deltaZPhe-G1y-OMe (R1, R2: CH3, 14CH3), the precursor of tentoxin, was obtained in a 72% yield from Boc-Leu-Gly-OH. This linear tetrapeptide, labelled with carbon-14, was used for a comparative study of four cyclization reagents DPPA, DCC-PfpOH, HBTU and HATU. This last was the most effective and gave tentoxin in a 81% cyclization yield. The activated ester formed with this reagent displayed an enhanced capacity for cyclization, permitting cyclization in concentrated medium (10 mM). This new synthetic route gave tentoxin in a 60% yield from Boc-Leu-Gly-OH and offers a means of achieving the synthesis of hitherto elusive analogues.