Sept. 20, 1962
3393
COXlMUNICATIONS TO 1 I I E E D I T O R
Total XeF4 taken: 0.4006 g . ; X e : found 0.2507 g., calculated 0.2537 g.; F : found 0.1435 g., calculated 0.1469 g.; H F : found 7.53 milliequiyalents, calculated 7.73 milliequivalents. Xenon tetra.fluoride is a colorless solid. It has a negligible vapor pressure a t -78' and roughly 3 nim. a t room temperature. It can be sublimed FOM-LABORATORIUM VOOR MASSASCHEIDINC KRUISLAAX 407 N A I M BOELRIJK easily a t room temperature. Samples of XeF4 AMSTERDAM0 T. P J H BABELIOWSKY sealed under vacuum in a glass tube grow to large, RECEIVED JULY 23, 196% colorless crystals within a few hours. The compound is stable at room temperature and has been stored unchanged in nickel or glass vessels XENON TETRAFLUORIDE' for over a week. XeF4 in a thin-walled Pyrex capilSir : The first true coinpound of xenon, Xe+PtFe-, lary was observed not to melt up to 100°. Xenon tetrafluoride appears to be insoluble in recently was reported by Bartlett.? This suggested to us the possibility that under some conditions of and does not react with n-C7F16. A preliminary scan of the infrared spectrum of temperature and pressure xenon might be oxidized by elemental fluorine. We have now found that the vapor has been made from 4000 to 400 cm.--', xenon and fluorine react readily to form a solid com- and only one strong band was found. This is at 290 cm-l, in the region where fluorine-metal pound XeF4 that is stable a t room temperature. One part xenon and approximately five parts of stretching frequencies usually are found. That fluorine by pressure were mixed in a 130 CC. nickel there is only one stretching frequency indicates high weighing can. The mixture was heated at 400' for symmetry of the gaseous molecule, consistent with one hour and then cooled rapidly to room tenipcra- either a tetrahedral or square pianar structure. Several weighed samples of XeF, were hydrolyzed ture with a water bath. The can was weighed before and after admitting the xenon and again after with dilute NaOH and the total amount of evolved the reaction when the excess fluorine had been gases was determined by P VT measurements. pumped off with the can in a -78' bath. The fluo- Upon hydrolysis with either dilute KaOH or HzO, a rine was pumped through a U-tube in a - 195' bath yellow product was formed which slowly dissolved in order to collect any unreacted xenon. N o unre- to give a clear, pale yellow solution. One might acted xenon was found when the reactions were expect the hydrolysis t o proceed according t o the carried out with excess fluorine. X separate experi- reaction ment with pure xenon had established that i t can be S e F i + L":O -+ S e + 0, + 4€1F (2) caught quantitatively in a - 195' bath. dnalysis for total fluoride is in agreement with this Table I shows the results of formula deterinina- equation. However, the amount of gas liberated tions based 011 the coiiibining weights of xenon and and the ratio of xenon to oxygen are not in agrecfluorine. nient with equation ( 2 ) . This indicates that the TABLE I chemistry of hydrolysis is inore complex. The CllUMlCAL Z'OKMULA O P X E S O N 1"LUORIDE nature of the hydrolysis reaction is being imestiXe taken, 1'2 consumed, Atom ratio gated further. l'reparatiuu millimoles millimoles F/Xe Preliminary studies of the reaction of fluorine or 9 "48 I 4.558 4.05 XeFd with excess Xe a t 400' indicate the existence 3 1,806 3.539 3.92 of a lower fluoride of xenon.
This work was done as part of the research program of the "Stichting voor Fundamenteel Onderzoek der Materiel' (Foundation for Fundamental Research on Matter) with the financial support of the "Nederlandse Organisatie voor Zuiver Wetenschappelijk Onderzoek" (Z.W.O.).
e.-
3 4
1.944 2,745
3.808 5,453
3.91 3.97
In another method to verify the formula, a weighed sample of the compound was heated in a weighing can with excess hydrogen a t 400' t o form hydrogen fluoride and xenon. The excess hydrogen was pumped off with the can in a - 195' bath. The material was then distilled under high vacuum through two nickel U-tubes in series. The first was in a - 159' bath so as to trap the hydrogen fluoride and pass the xenon. The second U-tube was in a -1105' bath to trap the xenon. The xenon was transferred to a weighing can and weighed and its identity and purity checked by mass spectrometric analysis. The hydrogen fluoride was weighed, hydrolyzed in a known excess of NaOH and determined both by back titration with HC1 and a fluoride analysis. The reduction was found to proceed according to reaction (1) XeF4
+ 2Hz --+Xe + 4 H F
(1)
(1) Based on work performed under the auspices of the U. S. Atomic Energy Commission. (2) N. Bartlett, Proc. Chem. Soc., 218 (1962).
&I. CLAASSES H E X K YSELIC J O I I N G. KILN
kIU!VARE A R G O N N E N A T I O N A L 1,ARORATORY
XRGUNNE,ILLINOIS RECEIVED AU(:C.ST '20, 19W
PRODUCTION AND REACTION§ OF METHYLENE IN THE TRIPLET STATE
Sir: the grouiid state Uiilike singlet methylene, triplet5is difficult to generate in the vapor phase.5,6,7 However, inasmuch as the spin angular momentum is conserved in mercury photosensitized reactions, as believed, i t would be expected that in the triplet mercury (Hg 63P1)photosensitized decomposition of ketene and diazomethane triplet methylene (1) W. von E. Doering and P. LaFlamme, J . A W L C. h e i i i . Soc., 7 8 , 3447 (1956). (2) P. S. Skell and R. C. Woodworth, ibid., 7 8 , 4496 (1956). (3) R. C. Woodworth and P. S. Skell, ibid., 81,3383 (1959). ( 4 ) H. M. Frey, Proc. Roy. SOL.(London), A261, 575 (1959). ( 5 ) G. Herzberg a n d J. Shoosmith, S a t u r e , 183, 1801 (1959). (6) F. A. L. Anet, R. F. W. Bader and A. h l . Van der Auwera J. A m . Chcm. Soc., 82, 3217 (1960). (7) H. M. Frey, ibid., 83, 5947 (1960).
3394
COMMUNICATIONS TO THE EDITOR
VOl. 84
should be formed. In view of this we have now from C4 t o C1 (probably via a cyclic intermediate) ; carried out such experiments with ketene and found (2) hydrogen migration from C2 to C1 (1,2-shift of that triplet methylene is formed, as shown by its hydrogen); (3) hydrogen migration from C2to C3 nonstereospecific reactions with b ~ t e n e - 2 ~ ~and ~ ~ 7 ~(1,2-shift 8 of hydrogen) ; (4) methyl migration from lack of random CH insertion reactions. C 2 to C1 or to C 3 (1,2-shift of methyl, occurring We have studied reactions of triplet methylene perhaps partly or entirely externally). generated in this manner with cis- and trans-buteneThe products from these migrations in the case of 2 and isobutene. I n all experiments the ratio of cis- or trans-butene-2 would be (1) 3-methylbuteneketene to oiefiii was 1:lO. At lower pressures the 1, (2) 2-methyl-butene-2, (3) 2-methylbutene-1 product composition varied as a result of secondary and (4) cis- and trans-pentene-2 and 3-methylbureactions of the non-stabilized "hot" adduct, as is tene-1, and in the case of isobutene, (1) 2-methylalso observed in the reactions of singlet m e t h ~ l e n e . ~butene-1, ( 2 ) 2-methylbutene-8 and (3) 3-methylSteady values were obtained in the case of cis- and butene-1. Examination of the product composition trans-butene-2 a t approximately 50 cm. and, in the shows that the probability of these reactions appears case of isobutene, a t about 20 cm. The composition to be in the order (4) > (1) > (2) > (3) for cis- and of the products in the high pressure region, ex- trans-butene-2 and (1) > (2) > (3) for isobutene. pressed as percentage of the total Cb compounds, In the case of isobutene (4) is structurally not possiis shown in the table. ble. This rearrangement scheme is consistent for the three olefins so far examined, but should of TABLE I course be verified on a much larger number of exIlirnethylamples. Further studies of the reactions of triplet cq clopropane Pentene-2 232inethylene are in progress. Cis- l l ' Q l l S hie" bleb hleC Reactant lrnifs-Butene-2 ci5-Butene-2 cis-Butene-Zd Isobutene
1,2 13.5 21.6 28.1 ,.
1,2
1,I
cis
trans
51.9 31.3 27.1
.. .. ..
5.6 19.3
18.7 0 . 7 12.3 0.7
17.0
16.5
..
..
01.0
..
B-I
B-1
B-2
..
6.8 2.8 8 1 3.7 10.5 4 . 0
6.5
0.5 2.3
2-Metliylbutene-I. b 3-Methy-lbutene-1. 2-Methylbutene-2. The values obtained from diazomethane photolysis in the presence of excess inert gas (ref. 7). a
Unlike singlet methylene, the triplet is seen to react nonstereospecifically with butene-2 and to give far more dimethyl-cyclopropane and 3-methylbutene-2. In the case of cis-butene-2 the results can be compared with those obtained from diazomethane photolysis in the presence of excess inert gas,I with which they agree reasonably well. In the isobutene reaction, comparison with singlet methylenegVl0 shows a large increase in the amount of 1,ldimethylcyclopropane with corresponding reduction in the yields of other products. The suggested mechanism for reaction of triplet methylene with olefins involves initial formation of a triplet addition complex (biradical I), in which partial rotation around the original carbon-carbon double bond is permitted and is responsible for the nonstereospecific formation of addition products. K,
I1
H
In the biradical I, lil = I3 and Rz = CHI for cis- and trans-butene-2, and R, = CH3and Rz = H for isobutene. Closure of the C1C2C3ring gives the corresponding dimethylcyclopropane. Since there is no evidence for random insertion of triplet methylene into CH bonds, the olefinic Cg products must be formed by rearrangement. This could occur by niigration of H,and perhaps of CH3 as well, in the biradical, ie. (1) hydrogen migration ( 8 ) K . R. Kopecky, G S. Hammond and P. A. Leermakers, J . Am. Chem. Soc., 84, 1015 (1902). (9) H. M.Frey, Proc. R o y . SOL.(London), A260, 409 (19.59). (10) J. H. Knox. A. F. Trotman-Dickenson a n d C. H. J. Wells, J . Chem. Soc., 2897 (1958).
(11) National Research Council Postdoctorate Fcllow.
F. J. UUKCAN" I)IVISIONO F APPLIED CHEMISTRY NATIONAL RESEARCH COUNCIL OF CANADA OTTAWA, ONTARIO K. J. CVETANOVI~: RECEIVED JULY 16, 1962 A NEW CARBOCYCLIC STEROID STRUCTURE : 12,lS-CYCLOSTEROIDS
Sir: The steroid nlolecule has been subjected to the most varied chemical and photochemical transformations. Among the most interesting recent changes have been those involving the angular methyl groups,' resulting in the inclusion of the C-19 methyl group in cyclopropanolj and cyclobutano'j structures and the C-1s methyl group in cyclobutanold and cyclopentano" structures. Phyllanthol, cycloartenol, cyclolaudenol, and cycloeucaleno13 possess the angular methyl groups in the cyclopropano arrangement. We wish to present herein the synthesis of the iiiteresting pentacyclic 12, IWehydrosteroidal ring system and the iiitcrconvertibility of the latter with the conaninc structure. (1) ( a ) IS. J. Coreg and N . R . IIertlei, . I . .4m,Chem. Snc., SO, 2903 (19;s); 8 1 , 5200 ( 1 9 5 9 ) ; (b) P. Riich,;chncher, J. Kalvoda, D. Arigoni and 0. Jeger, ibid., 80, 290.; (1!)58), ( c ) F. Greter, J. Kalvoda and 0. Jeger, Proc. Chcin. > o r . , 3-19 ( 1 9 i R ) ; (d) P. Buchschacher, hl. Cerephetli, H. Wehrli, K . Schaffner and 0. Jeger, f Z f l u . Chim. A c l n , 42, 2122 (19.59); N . C. V a n g and D. 11. Yane, Telrnhedron L e t f e r r . n o . 4 , I O (l9tiO); (e) G. Cainelli, hl. Lj. hlihnilnvic, I ) . Arigoni and 0. Jcxer, Ilelu. Chiin. A c t a . , 42, 1124 (1959); ( f ) C h . Meystre, K. Heusler, J . Kalvoda, P. Wieland, G. Anner and A. Wettstein, E x p r r i e a f i n , 11, 47,i (19lll\: (g) 1). H. R. Barton. J. hl. Beaton, I,. E:. Geller and RI. hl. Pechet, J . A m . C h r m .Tor., 82, 2610 (1900); r). H. R. Bart(m and J. M. Beaton. i b r d , 82, 20-11 (1960); A. L. Nussbaum. F. E. Carlon, E. P. Oliveto, E. Townley, P. Kabasakalian, and D. H. R. Barton, ibid., 82, 2973 (1000): D.H. R. Barton, J. M. Beaton, L. E. Geller and M. M. Pechet, ibid., 82, 4076 (1961) ; D. H. R. Barton and J. M. Beaton, ihid., 83,4083 (19G1); M. Akhtar and D. H. R. Barton, i b i d . , 84, 1496 (1962); (h) M Akhtar and D. H. R . Barton, ibid., 83, 2213 (1961); ii) D. H. R . Barton and L. R. Morgan, P r o c . Chem. Soc., 20ci (1901); (j) H. Wehrli, hI. S. Helbr, R. Schaffner and 0. Jeger, H c h . Chim. A c ~ Q44, , 2162 (1961); (k) far a review article, see K. Schaffner, D. Arigoni and 0. Jeger, Experienfia, 16, 169 (1960). (2) D. H . R Barton and P. deMayo, J . Chem. Soc., 2178 (1953). (3) For a summary of evidence, see L. F. Fieser and M. Fieser, "Steroids," Reinhold Publishing Carp., New York, N. Y., 1959, pp.
386-389.
