Solubility of Helium in Lithium Silicate Melts

Abstract

V [4] (Hg salt: m.p. 128 to 129 "C.) with n-butyllithium [3]. Thus, it is easier to remove a bromine cation from compound 11 than a proton [5]:GHsLi I1 ---+ (%H&P=CHz + (CnHs)P=CHBrThe desired bromomethylenation can be realized with lithium piperidide 161 which predominantly removes protons from 11; subsequent reaction with p-ionone (VI) gives, after chromatographic purification, the very unstable compound VII in 70 % yield (Amax = 269 mp; log E = 4.18).I thank Prof. G. Wiffig for his assistance in this work. [5] D . Seyferfh et al. have made the same observation. (Private communication by Prof. Seyferth.) [6] This also gives the best yields in chloromethylenation: G. Wittig and M. Schlosser, unpublished. I thank Dr. M. Schlosser for this communication.