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Cyclic imines can be conveniently prepared from w-azidoketones by an intramolecular 'aza-Wittig' reaction.The addition of a tertiary phosphine (i.e. triphenylphosphine) to an organic azide producing an iminophosphorane after nitrogen extrusion originally reported by Staudingerl has received little attention by synthetic chemists.2 The iminophosphoranes are known to react with benzaldehyde, for example, to give the corresponding Schiff base in a Wittiglike ('aza-Wittig') r e a ~t i o n . ~ This route to imines is of no use if the corresponding primary amine is easily accessible and if both reagents and product are stable under the reaction conditions usually used for such a condensation. If this is not the case, the 'aza-Wittig' reaction could be very useful. We report a new efficient route to the cyclic imines (3), involving an intramolecular 'aza-Wittig' reaction according to Scheme (1). Although there are a number of methods in the literature for the preparation of cyclic i m i n e ~, ~ they all suffer from severe limitations.The addition of 1.0 equiv. of triphenylphosphine to a solution of the azide (1) in anhydrous ether under nitrogenScheme 1

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