Synthesis of racemic eleutherin-quinones

604

ABSTRACTS

Peroxides of elements other than carbon. Part ZZZ., M. H. Abraham and A. G. Davies, J. Chem. Sot., 1959, 429-38. Autoxidation of 43 mg. of tert-butylboron is described. (See specifically p. 438.)

Organic Microsynthesis The isolation, characterization, and chemical synthesis of muramic acid, R. E. Strange and L. H. Kent, Biochem. J., 71, No. 2, 333-39 (1959). The material, a 3-o-a carboxyethylhexosamine, was obtained from germinating spores of R megatherium. The synthesized material checked out with the natural. Stereochemistry of ergot alkolids of the agroclavin and elymoclavin types, E. Schreier, Helv. Chim. Acta. 41, 198497 (1958). Microreactions on ergot alkoids are described. Constitution of jamaicin, Acta, 41,2006-21(1958).

0. A. Stamm, H. Schmid, and J. Biichi, A proof of structure of jamaicin is given.

Helv.

Chim.

Synthesis of racemic eleutherin-&nones, W. Eisenhuth and H. Schmid, Helv. Chim. Acta. 41, 2021-41 (1958). Synthesis of racemic eleutherin quinones from naphthol derivatives is described. On the structure of triter-penes 196. Constitution of soya sapogenols A, B, C and D, G. Cainelli, J. J. Britt, D. Arigoni, and 0. Jeger, Helv. Chim. Acta, 41, 2053-58 (1958). New data on the structure of soya sapogenols A., B, and C and a revision of the formula of soya sapogenol D are given. Degradation studies on cinobufugin, J. P. Ruckstuhl and K. Meyer, Helv. Chim. Acta, 41, 212134 (1958). Empirical formulae are confirmed, and a partial proof of structure is given. Doubling reactions during ring closure of peptides. ZZ. Cycloglycyl glycyl-DLUse of activated esters for the synphenylalanyl glycyl glyeyGn~phenylalany1. Molecular weight determination in dimethyl suljthesis of macrocyclic peptides. oxide, R. Schwyzer and P. Sieber, Helv. Chim. Acta, 41,2190-99 (1958). Cyclizations of peptides via activated esters are described. On the constitution of calabash alkaloids C-dihydro toxijerin-and C-toxijerin Z and of the alkaloid curacurin V from Strychnos toxifera, K. Bernauer, V. Berlage, W. Philipsborn, H. Schmid, and P. Karrer, Helv. Chim. Acta, 41, 2293-2308 (1958). Proofs of structure of C-toxiferin I and C-dihydrotoxiferin are given. Structure of ubiquinone from swine heart, R. A. Morton et al., Helv. Chim. Acta, 41, 2343-57 (1958). A study of the structure of ubiquinone shows it to be henzoquinone with a vitamin K-like side chain. MICROCHEMICAL

JOURNAL,

VOL.

III,

ISSUE

4