?-Chlor-nitrone IV: Zur Stereochemie der ?-Lacton-Synthese und eine Methode zum Aufbau von ?-Methyliden-?-lactonen aus Olefinen. �ber synthetische Methoden, 8. (vorl�ufige) Mitteilung
The Ag+-induced reaction between N-cyclohexyl-α-chloro-propionaldonitrone and the two diastereomeric 2-butenes in liquid SO2 is a stereospecific cis-addition. The use of N-cyclo-hexyl-α,β-dichloro-propionaldonitrone in this type of reaction provides a preparative route from olefines to α-methylidene-butyrolactones.