FIELD: chemical technology. SUBSTANCE: invention proposes to synthesize isoprene, formaldehyde and isobutylene from high-boiling by-side products of isoprene synthesis from formaldehyde and isobutylene, technical fraction of methyldihydropyrane or their mixture. Synthesis is carried out on catalytic surface consisting of solid contact at specific surface 0.2-1.0 m2/g and oxide aluminosilicate-containing catalyst including aluminium, iron, magnesium, calcium, sodium, titanium and silicon oxides. Composition consists of four layers at mass ratio contact : catalyst : contact : catalyst = (0.5-3.0): (3.0-7.0): (0.1-2.0):(3.0-7.0). Process is carried out at 350-550 C in the presence of steam and 0.02-5.0 wt.-% of ammonia. Proposed method ensures to utilize by-side products of isoprene synthesis, increase total yield of useful products up to 12% and decrease coke formation by 1.5-fold. EFFECT: improved method of synthesis. 2 cl, 4 tbl, 7 ex
