Selective reduction of peptidic ergot alkaloids

Five 6'-deoxoergopeptines were prepared in 51-68% yield by selective reduct ion of parent alkaloids with lithium aluminium hydride in tetrahydrofuran a t low temperature. New compounds were characterized by mass spectrometry an d NMR spectroscopy. The conformation of the peptide part in starting compou nds and reduced derivatives is discussed on the basis of crystal structure determination of 6'-deoxo-9,10-dihydroergotamine dihydrate butan-2-one solv ate as a representative member of the series.