Sept., 1943
COMMUNICATIONS TO THE EDITOR
larger than those proposed herein may eventually be adopted, but no convincing reason for such a step is apparent now. Fitting the porcupine quill data to 658 A. is not critical, since no meridional spacings larger than one-tenth this value have been found, although they have been sought in this Laboratory. MacArthur’s arguments were based largely on the position of a prominent short-spacing meridional arc (5.14 A.), and on the expectation that a multiplier such as 128 (23O) should yield from i t the true fiber-axis period. The 5.14 8. arc is located in a region of considerable diffraction structure and may possess a layer-line component, so that its consideration is not an unambiguous matter. Also, a similar line of reasoning applied by Astbury to the collagen fiber-axis period was not conspicuously successful.l s 3
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VI
VI1
Their first claim is open to dispute if they intend to claim that fused ring systems linked through vicinal nitrogen atoms are new. Two compounds of this class 2,3-phthalophthalazl,4-dione (111) and 3-phenyl-1,2-phthalopyrazoline (IV) were described by Drew and Hatt2 and their preparation occasioned a search of the DEPARTMENT OF BIOLOGY AND BIOLOGICAL ENGINEERING the literature for other compounds containing MASSACHUSETTS INSTITUTE O F TECHNOLOGY CAMBRIDGE, MASSACHUSETTS RICHARD S. BEAR this structural feature. A number have been found, most of which are listed in the “Ring Index” AUSUST12, 1943 RECEIVED of Patterson and Capell (Nos. 465, 535, 581, 608, 908, 1361, 2264 and 3463). Only two comHETEROCYCLIC NITROGEN. COMPOUNDS AND pounds (V) have been found of this kind which THE STEREOCHEMISTRY OF TERVALENT are not either specifically mentioned in the NITROGEN Ring Index or referred to in the literature it Sir: cites and they are of Ring Index Type R. I. 581.3 Buhle, Moore and Wiselogle’ when reporting Number 608 of the Ring Index (formula (11) the preparation of 1,2-trimethylenepyrazolidine above) is of interest since it contains the same (I) claimed i t as the first bicyclic compound of condensed ring system as the trimethyleneits type, and considered that in proposing to pyrazolidine (I) of Buhle, Moore and Wiselogle. study the stereochemistry of thi; class of com- Our concern here is to list the prior claims to pound they would be approaching the problem have prepared compounds having this structural of the resolution of tervalent nitrogen compounds feature and not to consider the validity of those in a new manner. claims. As regards their second claim for a novel approach to the problem of resolution of tervalent nitrogen compounds, i t was appreciated when compound (111) was prepared that because of its I structure it had especial interest with regard to the stereochemistry of tervalent nitrogen and this was mentioned.2a Substitution a t the marked hydrogen atom of (111) renders the molecule, if non-planar, asymmetric and therefore theoretiI1 cally resolvable. The preparation of such subH* stituted compounds has been in progress for sometime and an account of the preliminary preparational work was recently submitted for publication to the Journal of the Chemical Society. In it the preparation of compound (VI) is de111
IV
(1) Buhle, Moore and Wiselogle, THISJ O U R N A L . 66, 2Y (1943).
(2) Drew and Hatt, J Chrrn Soc (3) btolle, Bet , 46, 277 (1912)
,
I b (1337), (a) d a d , p 19
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COMMUNICATIONS T O THE
EDITOR
\'ol. 65
Several products of catalytic hydrogenation of bethogenin have been isolated. The absorption of one mole of hydrogen in the presence of platinum in alcoholic solution removes methoxyl to give a product which contains both a double bond and a THE UNIVERSITY OF MFALUOURNE H. H. HATT carbonyl group and which forms a diacetate, MELBOURNE, AUSTRALIA EMILYI?. H. STEPHENSON C31H4606, m. p. 142-144O, [a]24~-156' in diRECEIVED APRIL28, 1943 Exhaustive catalytic reduction of bethooxane. .. .genin in alcoholic solution gives C27H4604, m. p. SAPONINS AND SAPOGENINS. XXIII. THE 203--208.6', [(rIz6D -57.7' in dioxane. This CONSTITUTION OF BETHOGENIN' product no longer contains a double bond or a Sir: carbonyl group. On reaction with acetic anhyWe should like to propose the following strucdride in pyridine i t loses one molecule of water arid tural formula for hethogenin.*s3 f o r m a monoacetate, Cz9H&04,m. p. 204-207.5', / O - CHOCHi [ a l S 5-62.2' ~ in dioxane. On mixing with tigo\
