EXPERIMENTS ON THE SYNTHESES OF FURANO COMPOUNDS.

Attempts to prepare 3-benzylcoumarones of the type (I, R = acyl) designed for a different syn­thesis of β-brazans have not been successful. Contrary to the observations of Gilman and his co-­workers, it is shown that the cyclisation of the acid (XI) gives a mixture of the ketones (XII) and (XIII) ; the former has been converted into 7-hydroxy-and 7-methyl-β-brazan. Experiments on the cyclisation of the pyrnvic acid of the type (XVII, R"=CH₂.CO.CO₂H) to the \(\gamma\)-brazan (XV, R"=CO₂H) have been so far unsuccessful. However, the hydroxy-\(\gamma\)-hrazan (XV, R=OMe, R'=Me, R''=OH) has been synthesised according to the method of Jhonson and Robertson.