Auf das Zentralnervensystem wirkende Substanzen XXV. Reaktionen der α‐substituierten β‐Lactone II. Eine neue allgemeine Synthese α‐substituierter Propionsäuren und deren Derivate

Hydrochloric acid and hydrobromic acid react with α‐mono‐ and α, α‐disubstituted β‐lactones under ring cleavage leading unequivocally to the corresponding α‐mono‐ or α, α‐disubstituted β‐halogenopropionic acids. These products are interesting starting materials for the preparation of new compounds and can be reduced by zinc and formic acid to the corresponding propionic acids. The described synthesis is a general one and may be carried out with good yields. Moreover it has been observed that the new α, α‐disubstituted β‐halogenopropionic acids can be reconverted to the β‐propiolactones by the action of alkalies or by zinc in neutral or slightly acidic medium.