It has been reported that 2-chlorotropone and 2-methoxytropone react with ethyl cyanoacetate or malononitrile, in the presence of sodium ethoxide, to give azulene derivatives. 1) On the other hand, 1-oxaazulan-2-one (2H-cyclohepta [b] furan-2-one) derivatives have been obtained by the reaction of these tropone derivatives and diethyl malonate or ethyl acetoacetate. 2) We have reexamined these reactions with an interest in ...