198 VITAMIN D GROUP 



ported values, but inferior to the value 19,400 (A'}f^. = 490) found by 

 Penau and Hagemann^^" and Crews and Smith.-^"" 



Calciferol gives no precipitate with digitonin. In the well-known color 

 reactions, it generally gives weaker and less well-defined colors than ergos- 

 terol. These responses are described by Askew et al.,'^^^ Windaus et al.,^^^ 

 and Bacharach et aZ.-'*^ Color reactions of special interest in connection 

 with vitamin D are described by Pesez,^^^ Banchetti,-^^ Schaltegger,^^^ Villar 

 PalasI,^'"' and De Witt and Sullivan-^" 



The structural formula of calciferol (Fig. 13) was established by Windaus 

 and Thiele^o^ ^^-^ 1935 ^nd by Heilbron et al.^^^ in 1936. Their published work 



TABLE VII 

 Optical Rotation of Calciferol" 



Solvent [a\\l,, [«l'„° Ratio 



Alcohol (absolute) -fl25.0° +106.25° 1.18 



Ethyl acetate +113.25° +95.0° 1.19 



Ether +105.5° + 88.75° 1.19 



Benzene +102.12° +87.5° 1.17 



Acetone +99.5° +83.5° 1.19 



n-Hexane +66.5° + 56.25° 1.18 



Chloroform + 61.75° + 52.25° 1.18 



Average value of ratio = 1 . 18 



" Data from Bacharach et al.^^^ on commercial lots of refined material. 



was the culmination of a long series of attacks on the problems of structure 

 which are reviewed by Fieser and Fieser"^ and by Rosenberg. ^^ The cor- 

 rectness of the formula has been confirmed, and detailed stereochemical 

 relations of the atoms within the molecule established, by Crowfoot and 

 Dunitz^"* through a study of the X-ray diffraction pattern of calciferyl 

 4-iodo-5-nitrobenzoate. 



g. Toxisierol. Substance 2^8 



C28H44O. Melting point about 50°.^"^ Narrow absorption band with max- 

 imum at 248 m/x ; molecular extinction coefficient = 18,300.''^ [ajo = —16° 

 (in chloroform).*"* 



298 A. Banchetti, Ann. chim. appl. 38, 394 (1948). 



299 H. Schaltegger, Helv. Chim. Acta 29, 285 (1946). 

 3«oV. Villar Palasi, Nature 160, 88 (1947). 



s"! J. B. De Witt and M. X. Sullivan, Ind. Eng. Chem. Anal. Ed. 18, 117 (1946). 



302 A. Windaus and W. Thiele, Ann. 521, 160 (1935). 



303 I. M. Heilbron, R. N. Jones, K. M. Samant, and F. S. Spring, J. Chem. Soc. 1936, 

 905. 



30* D. Crowfoot and J. D. Dunitz, Nature 162, 608 (1948). 

 305 o. Linsert, U. S. Pat. 2,030,377 (1936). 



