ChemInform Abstract: SYNTHESIS OF 5‐AMINO‐9‐(β‐D‐RIBOFURANOSYL)‐V‐TRIAZINO‐(4,5‐B)PYRIMIDO(4,5‐D)PYRROL‐4‐ON# E AND UNUSUAL RING OPENING OF THIS NEW RING SYSTEM WITH THE VILSMEIER‐HAACK REAGENT