No abstract

No abstract

THE presence of an unidentified base in the mother-liquors after the isolation of spermine phosphate from tissue extracts was originally observed by M. C. Rosenheim and 0. Rosenheim during their early work on spermine and has already been reported [Dudley, Rosenheim and Rosenheim, 1924]. This base has been given the name spermidine since it not only occurs in association with spermine but also has been found to be structurally related to the latter substance. Its phosphate is much more soluble than that of spermine and crystallises from the 25 % alcoholic mother-liquor, after the removal of spermine phosphate, on increasing the concentration of alcohol to about 50 %.

No abstract

19381 Steroids and Related Cmfiwnds. Part I I . 677 120. Steroids and RekLted Compounds. Part I I . The Dehydration of Cholestanetriol. By V. A. PETROW, 0. ROSENHEIM, and W. W. STARLING.An unsaturated diol C&&2 has been obtained by a Darzens dehydration of cholestane-3 : 5 : &trio1 diacetate, and its constitution as a Ad-cholestene-3 : 6-diol established. This constitution had previously been assigned to two isomeric diols of the same empirical composition (to be referred to as Lettr6's and Westphalen's diol) which were obtained from the trio1 by different methods. It is now shown that Lettrk's unsaturated diol C,7H4,0, is a saturated keto-alcohol identical with 6-ketocholestanol, C,,H4,02. Evidence in favour of the constitution of Westphalen's diol as 5-methyl-A8:9-norcholestene-3 : 6-diol has been obtained and it is concluded that only one of the four possible stereoisomerides of A4-cholestene-3 : 6-diol is obtainable by the dehydration of cholestane-3 : 5 : 6-triol.WHEN attempting to enforce acetylation of the tertiary hydroxyl of cholestane-3 : 5 : &trio1 diacetate (11; R = Ac, R, = OH) by treatment with acetic anhydride and sulphuric acid, Westphalen (Ber., 1915, 48, 1064 cf. Dunn, Heilbron, Phipers, Samant, and Spring, J., 1934, 1580) obtained the diacetate of an unsaturated diol C2,H4,02, to be referred to as Westphalen's diol. Lettr6 and Inhoffen (" uber Sterine u.s.w.," 1936, p. 33; cf. Petrow, J., 1937 cf. Petrow, J., , 1077 ascribed to this diol the constitution of a A4-cholestene-3 : 6-diol (I, R = H). Lettr6 and Miiller (Ber., 1937, 70, 1947) were forced, however, to discard this view when -(VII.) they found that on oxidation (at 4") the diol did not yield the expected unsaturated diketone (IV), but a substance C,,H4,0, (?), m. p. 143", which was not further characterised. They suggested that the diol might possibly have the constitution (IX).We have now obtained, on oxidation at room temperature, an unsaturated diketone C2,H4,02, m. p. 106", which was characterised by a bis-2 : 4-dinitrophenyZhydrazo.ne, m. p. 218", and a mono-o-toZyZsemicarbazone, m. p. 235". Of the possible constitutions of the diketone, we favour (XI), 5-methyZ-AE:9-norchoZestene-3 : 6-dione, on the assumption that the positions of the functional groups are identical in the diketone and the diol. The evidence for the proposed constitutional formula is based on the following facts :(1) Westphalen's diol is not precipitated by digitonin, showing that the spatial position of the angular methyl group at C,, relative to the hydroxyl at C3 has undergone a change during dehydration (cf. the non-precipitability of lumisterol, Dimroth, Ber., 1936,69, 1123. This conclusion was strengthened when it was found that (2) the diol and its esters are strongly dextrorotatory : an increase of dextrorotatory power is known to follow changes in the relative position of the 10-methyl and the 3-hydroxyl group (cf. Callow and Young, Proc. Roy. SOC., 1936, A , 890,194). Further, (3) the diol and its esters gave a typical green On hydrolysis of the...