Description:
Total synthesis of verrucarin E. Its application to the preparation of a 13C‐labeled derivative.A relative high over‐all yield synthesis of verrucarin E (3‐acetyl‐4‐hydroxymethyl‐pyrrole), a secondary metabolite of the soil fungus Myrothecium verrucaria, has been achieved by condensation of (E)‐5‐benzyloxy‐3‐penten‐2‐one with tosylmethylisocyanide and subsequent hydrogenolysis of the obtained O‐benzyl derivative. As the closure to the pyrrole ring takes place regiospecifically, this procedure is convenient for preparing verrucarin E labeled with C‐isotopes. On the basis of the data obtained from the 13C‐NMR. spectrum of Verrucarin E labeled with 13C at the C(2) and C(3) positions, all the 13C‐resonances of Verrucarin E could be assigned unambiguously.