UNEXPECTED TRANSFORMATION OF SPIRO-3-CYANOMETHYL-3-METHYL-1,2,3,4,5,6-HEXAHYDROBENZO[f] ISOQUINOLINIUM-1,2 '-(1 ',2 ',3 ',4 '-TETRAHYDRONAPHTHALEN-1 '-ONE) CHLORIDE TO SPIRO-3,4,5,6-TETRAHYDRO-2H-BENZO[h]CHROMENE-2,2 '-(TETRAHYDRONAPHTHALEN-1 '-ONE)

摘要

In a study of sigmatropic transformations of quaternary salts of various tetrahydropyridinium derivatives, we have discovered an unexpected cascade transformation of spirohexahydrobenzo[f]isoquinoli-nium-1,2'-(tetrahydronaphthalen-1'-ne) chloride (1) into spirotetrahydro-2H-benzo[h]chromene-2,2'-(tetrahydro-naphthalen-1'-one) (2). This reaction proceeds in the presence of moist triethylamine upon heating salt 1 in moist dioxane at reflux for 20 h. The structure of compound 2 isolated chromatographically in 40% yield was established unequivocally by GC/MS and 1H NMR spectroscopy as well as by comparison with the data of Quail et al. [4].