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COMMUNICATIONS TO THE EDITOR
Vol. 71
The results are summarized in Table I and compared with the quantities of free purines and pyrimidines found in acid hydrolysates of nucleic acids (Procedure 3).4 It will be seen that the nucleotide analyses presented here contribute to a more complete understanding of ribonucleic acid composition, mainly with respect to uridylic acid which has proved relatively resistant to formic acid hydrolysis. They also reveal remarkable differences between ribonucleic acids from different sources.
is converted in good yield to I1 (identified by reduction to 111). The silver bromide-catalyzed rearrangement affordsstrong experimental support to the hypothesis that silver bromide is a Lewis acid of sufficient strength to weaken observably the carbonbromine bond of an alkyl bromide. Limiting the establishment of a mechanism for the brominative decarboxylation is the corollary hypothesis that the alkyl bromide actually isolated, having been subject to alteration by silver bromide, is not necDEPARTMENT O F BIOCHEMISTRY ERWIXCHARGAFF essarily identical with the bromide produced iniCOLLEGE OF PHYSICIANS AND tially in the decarboxylation. Consequently, the BORISMAGASANMrearrangement observed in the decarboxylation of SURGEoN s COLUMBIA UNIVERSITY RUTHDONIGER NEW Y O = , N. Y. ERNSTVISCHER I may not, in the absence of further experimentation, form the basis for a mechanistic hypothesis. RECEIVED MARCH17, 1949 Similarly no mechanistic significance, is attributable to the optical inactivity of the 3-bromoheptane isolated from the brominative decarboxylaREARRANGEMENT OF 2-BROMOBICYCLO [2,2,2]0Ction of optically active silver heptane-3-carboxylTANE WITH SILVER BROMIDE ateIs in the absence of observations on the optical Sir: stability of 3-bromoheptane in the presence of silWe have found that the brominative decarboxy- ver bromide. lation' of a suspension of the silver salt of bi(8) Arnold and Morgan, THISJOURNAL, 70, 4248 (1948). cycle [2,2,2]octane-2-carboxylic acid2 (I) affords 2HAVEMEYER LABORATORY bromobicyclo[l,2,3]octane (11)) m. p. 39-41'. UNIVERSITY W. VON E. DOERING The structure of I1 is tentatively assigned on the COLUMBIA NEWYORK27, N. Y. M ~ L T OFARBER N grounds (a) that reduction with sodium and alcoRECEIVED MARCH5. 1949 hol gives bicyclo[l,2,3]octane (111) [Anal. Calcd. for CsH14: C, 87.19; H I 12.81, Found: C, 86.88; H, 13.141, m. p. 139.5-141') reported 133°3,4and IDENTIFICATION OF CRYSTAL141°5 and (b) th!at aqueous alcoholic alkali gives VITAMIN Biz. V. LINE VITAMIN Bits a n alcohol, m. p. 183-184', which is apparently identical with the bicyclo [1,2,3]octane-2-01, m. p. Sir: Catalytic reaction of vitamin BIZ with hydro183', of Alder and Windemuth6 by virtue of the similarity of the phenylurethan [Anal. Calcd. gen has yielded a crystalline product which shows for CI6Hl9O2N: C, 73.44; H, 7.81; N, 5.71. high hematopoietic activity in pernicious anemia, Found: C, 73.62; H, 7.74; N, 5.641, m. p. 128- although it is somewhat less active than vitamin 129.5', reported5 130' and the hydrogen phthal- Biz. To a solution of 26.3 mg. of vitamin BIZin 15 ate [Anal. Calcd. for CleH1804: C, 70.05; H, ml. of water, 78 mg. of platinum oxide catalyst was 6.61. Found: C, 70.11; H I 6.741, m. p. 118-119', added and the mixture was shaken with hydrogen reported6 116-1 17'. This rearrangement, the first example of the at atmospheric pressure for twenty hours. During conversion of the bicyclo [2,2,2]octane system to reaction, the red color changed to dark brown, but the bicyclo [1,2,3]octane system,6 has prompted on contact with air the red color returned indicatexamination of the effect of silver bromide on the ing changes in the cobalt ion. The filtrate from potentially initial product, 2-bromobicyclo [2,2,2]- the catalyst was evaporated in vacuo a t 25'. The octane (IV). Unrearranged IV [Anal. Calcd. for residue was dissolved in 1 ml. of water and 6 ml. of C8H13Br: C, 50.81; H, 6.93; Br, 42.26. Found: acetone was added. After several hours, 1-2 mg. C, 50.90; HI 6.89; Br, 42.131, m. p. 64-65.5", of precipitate formed and was removed. Acetone is prepared from bicyclo[2,2,2]octene2 by the (2 ml.) was added again and, after standing, 4-5 addition of hydrogen bromide in ether,7 and can mg. of precipitate was removed. Acetone (2 ml.) be reduced to bicyclo[2,2,2]octane (V), m. p. was added, and dark-red crystals formed during 169.5-170.5'. On treatment in carbon tetrachlo- twenty-four hours; yield, 12 mg. Further addiride either with silver bromide or with silver ace- tion of acetone yielded more crystalline material. After two recrystallizations from water by the tate and bromine but not with bromine alone, IV addition of acetone, the red crystals showed re(1) Cf.Kleinberg, Chcm. Res., 40, 381 (1947). fractive indicesla of a, 1.580; p, 1.640; and y , (2) Seka and Tramposch. Ber., 71, 1379 (1942). 1.654. The cobalt (4.58%) and phosphorus (3) Komppa, et at.. Ann., 121, 242 (1936). (4) Barrett and Linstead, J. Chcm. SOC.,611 (1936). (2.43%) content reveal that the BIZmolecule is not (6) Alder and Windemuth, Bcr.. 71, 2404 (1938). grossly altered. (6) The driving farce is plausibly derived from the relief of Pitzer strain [Beckett, Pitza and Spitz-, Tms JOURNAL, 69, 2488 (1947)l. (7) F o l l o Meerwcin ~ End von Emster, BM.,I S , 2500 (1922).
(1) Courtesy of (a) Dr. Charles Rosenblum; (b) Mr. David Hendlio; ( c ) Dr Gladys EmerPQn; (d) Dr. Walther Ott.
