AbstractDie Arylhydrazone (I) und (III) werden durch J od/K‐tert.‐butylat (Ktb) zu den E‐Arylhydrazonen (II) bzw. (IV) oxidiert.

Arylhydrazones of 5α-cholestan-3-one and lanost-8-en-3-one are dehydrogenated by iodine and potassium t-butoxide, and by nitrobenzene or p-nitrobenzoic acid and potassium t-butoxide, to the 1,2-didehydro- or 1,2,4,5-tetradehydro-analogues respectively in high yield.