@misc{PeterBoldtNiedersteinetal.1990,
  author    = {Peter, Martin G. and Boldt, Peter C. and Niederstein, Yvonne and Peter-Katalinić, Jasna},
  title     = {Synthesen von Galactose-Cluster-haltigen Steroid-Derivaten},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16783},
  year      = {1990},
  abstract  = {The synthesis of galactose clusters that are linked to a steroid moiety by a peptide-like spacer unit is described. The galactose cluster is obtained by Koenigs-Knorr glycosylation of TRIS-Gly-Fmoc (2b) under Helferich conditions. Peptide and ester bonds are formed after activation of carboxylic acids as diphenylthiophene dioxide (TDO) esters. 6a is synthesized in a convergent way by coupling of (Ac4Gal)3-TRIS-Gly (3e) with cholesteryl TDO succinate (5b). Coupling of (Ac4Gal)3-TRIS-Gly hydrogen succinate (3f) with Gly-O-Chol (5d) by means of EEDQ yields 6d. Reaction of (Ac4Gal)3-TRIS-Gly-SUCC-O-TDO (3g) with 25-hydroxycholesterol leads in a linear sequence to the oxysterol derivative 6f. Selective cleavage of the acetyl groups from galactose units yields the known compound 6b and the new derivatives 6e and 6g.},
  language  = {de}
}