Die Konstitution von Verrucarin J. Verrucarine und Roridine, 9. Mitteilung [1]

The antibiotic verrucarin J (C27H32O9) yields on base catalysed hydrolysis verrucarol (3), cis,trans‐muconic acid (5) and 5‐hydroxy‐3‐methyl‐2‐pentenoic acid lactone (6). 6 is a secondary reaction product of the genuine cis‐5‐hydroxy‐3‐methyl‐2‐pentenoic acid (10). In the antibiotic the three fragments 3, 5 and 10 are united to form a macrocyclic triester. Their sequence is deduced on the basis of the partial hydrolysis of verrucarin J leading to the dihydroxyester 11. Structure 1 is assigned to verrucarin J.