Catalytic transformations of 1,6-dioxaspiro[4,4]nonanes

Summary In the vapor phase over platinized charcoal at 300–320°, 2-and 3-alkyi-1,6-dioxaspiro[4.4]nonanes undergo the following transformations: isomerization of one of the tetrahydrofuran rings with formation of tetrahydrofuran oxo compounds, decarbonylation of tetrahydrofuran aldehydes, and isomerization of tetrahydrofuran homologs and tetrahydrofuran ketones to give aliphatic ketones and -diketones, respectively.