A Wittig Reaction that Gives Only One Stereoisomer Several Wittig reactions that use 50% sodium hydroxide as the base, and are thus suitable for undergraduate laboratories, have heen described recently in THIS JOURNAL.',^ The examples given result in the formation of eis-trans mixtures of alkenes. which must then be seoarated. I t has been reported that thr Wittigrracta,nof9-nnthraldchydruiththe ylrdderived irom ben~yltriphenylph