NOVEL SYNTHESIS OF THIANINHYDRIN

The synthesis of the previously reported thianinhydrin (12) was achiev ed from 3-methylthiophene via the corresponding 5,6-dihydrocyclopenta[ b]thiophen-4,6-dio (10). Conversion of 10 to the tricarbonyl (12) proc eeded in good yield using dimethydioxirane oxidation of 5,6-dihydro-5- dimethyl aminomethylenecyclopenta[b]thiophen-4,6-dione (14). The fluor escence intensity of the zinc salt of the product of 12 and glycine wa s similar to that obtained from the product of ninhydrin and the same amino acid. (C) 1997 Elsevier Science Ltd.