294 CAROTENOID CARBOXYLIC ACIDS XIII 



133. P. Karrer and F. Benz, Helv. chim. Acta 16 (1933) 337. 



134. P. Karrer and T. Golde, Helv. chim. Acta 13 (1930) 707; cf. P. Karrer and co- 

 workers, Helv. chim. Acta 15 (1932) 1406. 



135. P. Karrer , A. Helfenstein and R. Widmer, Helv. chim. Acta 11 (1928) 1207. 



136. K. W. Hausser and A. Smakula, Z. angew. Chem. 47 (1934) 663; 48 (1935) 152. 



137. P. Karrer and A. Helfenstein, Helv. chim. Acta 13 (1930) 392. 



138. R. Kuhn and P. J. Drumm, Ber. 65 (1932) 1459, ref. 6. 



139. R. Kuhn and A. Winterstein, Ber. 66 (1933) 209. 



140. R. Kuhn and co-workers, Ber. 63 (1932) 1785. 



141. P. Karrer and A. Helfenstein, Helv. chim. Acta 13 (1930) 397. 



142. P. Karrer and co-workers, Helv. chim Acta 11 (1928) 1207. 



143. R. Kuhn and F. L'Orsa, Ber. 64 (1931) 1735. 



144. H. Raudnitz and J. Peschel, Ber. 66 (1933) 901. 



145. P. Karrer, F. Benz and M. Stoll, Helv. chim. Acta 16 (1933) 297. 



146. P. Karrer and co-workers, Helv. chim,. Acta 15 (1932) 1408. 



147. F. Decker, Arch. Pharm. 252 (1914) 155. 



148. Dragendorf, Heilpflanzen 608, 1885. 



149. C. Liebermann, Ber. 44 (1911) 850. 



150. C. Liebermann and W. Schiller, Ber. 46 (1913) 1973. 



151. C. Liebermann and G. Muhle, Ber. 48 (1915) 1653. 



152. R. Kuhn and A. Deutsch, Ber. 66 (1933) 883. — . R. Kuhn and H. Brockmann, Ber. 

 67 (1934) 885. Ann. 516 (1935) 104. 



153. Cf. Y. Takeda and T. Ohta, Z. physiol. Chem. 258 (1939) 6. 



154. R. Kuhn and co-workers, Ber. 64 (1931) 333; 65 (1932) 1873. 



155. R. Kuhn and A. Deutsch, Ber. 66 (1933) 883. 



156. R. Kuhn, A. Winterstein and H. Roth, Ber. 64 (1931) 333. 



157. R. Criegee, Ber. 64 (1931) 260. 



158. R. Kuhn and A. Deutsch, Ber. 66 (1933) 883. 



159. R. Kuhn and A. Winterstein, Ber. 65 (1932) 1873. 



160. R. Kuhn and H. Brockmann, Ann. 516 (1935) 95. 



161. R. Kuhn and A. Deutsch, Ber. 66 (1933) 883. 



162. R. Kuhn and A. Deutsch, Ber. 66 (1933) 883. 



163. R. Kuhn and A. Deutsch, Ber. 66 (1933) 891. — Cf. R. Kuhn and H. Brockmann, 

 Ann. 516 (1935) 131- 



164. R. Kuhn and A. Deutsch, Ber. 66 (1933) 891. — Cf. R. Kuhn and H. Brockmann, 

 Ann. 516 (1935) 131- 



165. R. Kuhn and H. Brockmann, Ber. 6y (1934) 885; Ann. 516 (1935) 132. 



166. R. Kuhn and H. Brockmann, Ann. 516 (1935) i3i- 



167. R. Kuhn and H. Brockmann, Ann. 516 (1935) 132. 



168. R. Kuhn and H. Brockmann, Ann. 516 (1935) 133. 



169. R. Kuhn, A. Winterstein and H. Roth, Ber. 64 (1931) 340. — C. Liebermann and 

 G. Muhle, Ber. 48 (1915) 1653. 



170. R. Kuhn and A. Deutsch, Ber. 66 (1933) 890. 



171. P. Karrer, H. Obst and U. Solmssen, Helv. chim. Acta 21 (1938) 451. 



172. C. Liebermann and W. Schiller, Ber. 46 (1913) 1977. — R. Kuhn and co-workers, 

 Ber. 64 (1931) 338. 



173. R. Kuhn, A. Winterstein and H. Roth, Ber. 64 (1931) 333. 



174. R. Kuhn and H. Brockmann, Z. physiol. Chem. 221 (1933) 133. 



175. R. Kuhn and H. Brockmann, Ann. 516 (1935) 104, 134. 



176. R. Kuhn and H. Brockmann, Ann. 516 (1935) 136-137. 



177. R. Kuhn and H. Brockmann, Ann. 516 (1935) 136-137. 



178. R. Kuhn and H. Brockmann, Ann. 516 (1935) 139. 



179. R. Kuhn ,A. Winterstein and H. Roth, Ber. 64 (1931) 340. — Cf. C. Liebermann 

 and G. Muhle, Ber. 48 (1916) 1653. 



180. R. Kuhn, A. Winterstein and H. Roth, Ber. 64 (193 1) 339. 



