Preparation of 2,7-diazabicyclo(3.3.0)octanes

A process for the preparation of a 2,7-diazabicyclo-(3.3.0)octane of the formula ##STR90## where R.sup.1, R.sup.3, R.sup.4, R.sup.5, R.sup.7 and R.sup.8 may be identical or different and in each case denote H, C.sub.1 -C.sub.5 -alkyl (optionally substituted by halogen, hydroxyl or C.sub.1 -C.sub.3 -alkoxy), C.sub.1 -C.sub.3 -alkoxycarbonyl or C.sub.6 -C.sub.12 -aryl, or

• R.sup.1 additionally denotes halogen
• R.sup.2 and R.sup.6 may be identical or different and denote H, C.sub.1 -C.sub.6 -alkyl, benzyl, C.sub.6 -C.sub.12 -aryl, C.sub.1 -C.sub.3 -alkanoyl, benzoyl or C.sub.1 -C.sub.5 -alkoxycarbonyl, or
• R.sup.2 and R.sup.3 together denote a bridge of the structure (CH.sub.2).sub.n, CH.sub.2 --CHOH--CH.sub.2, CH.sub.2 --S--CH.sub.2 or C(CH.sub.3).sub.2 --S--CH.sub.2, in which
• n represents 2-4,
• comprising reacting an unsaturated carbonyl compound of the formula ##STR91## with an amino acid derivative of the formula ##STR92## in which R' represents H or C.sub.1 -C.sub.3 -alkyl,
• to effect an intramolecular 1,3-dipolar cycloaddition, and then optionally converting either or both of R.sup.2 and R.sup.6 to hydrogen.