April, 1939
COMMUNICATIONS TO THE EDITOR
973
The ene-diol is a white solid (plates) which melts ried through the remaining steps, which consisted first in lengthening the acetic acid chain to a pro- at 144-14.5' in a nitrogen-filled sealed tube. pionic acid chain through the Arndt-Eistert reAnal. Calcd. for C;OH2402: C, 81.04; H, 8.16. action. The dimethyl ester of the trans-7-meth- Found: C, 81.02; H, 8.01. oxy-1-propionic acid-2-methyl-2-carboxytetrahy- It can be kept indefinitely in an atmosphere of drophenanthrene (m. p. 101-102') was cyclized by dry nitrogen but when exposed to air autoxidizes sodium and the product was converted to d,l- rapidly even in the solid state, giving the correequilenin by the usual hydrolysis and decarboxyla- sponding benzil. The ene-diol rearranges t o tion, including the hydrolysis of the methoxy 2,4,6,2',4', 6'-hexamethylbenzoin under the influgroup. The synthetic equilenin crystallized from ence of hydrochloric acid or piperidine. It rebenzene in thin colorless plates which melted a t duces Tollens' reagent as well as cupric acetate 265-267' (natural equilenin, 258') to a red liquid. solution a t 0'. It is immediately oxidized by The structure of the synthetic equilenin was sodium 2,6-dichlorobenzeneoneindophenol. The established definitely by its conversion to 3',3'- isomeric benzoin does not react with Tollens' redimethyl - 7 - methoxy - 1,2 - cyclopenteno- agent or cupric acetate solution in the cold nor phenanthrene, identical with the compound ob- with the indophenol even when heated. tained from natural equilenin by the procedure 2,4,6-Triethylbenzoyl chloride gives a similar of Cohen, Cook and Hewett [ J . Chem. SOL,445 but even more stable ene-diol when treated with (1935) 1, the method employed by these investiga- the binary mixture. tors to establish the structure of equilenin. The These ene-diols are unique in that in them the synthetic equilenin was resolved by converting ene-diol grouping is not conjugated with a cari t to its I-menthoxyacetic ester, from which was bonyl group.3 However, it is conjugated with isolated the ester which proved to be identical two aromatic nuclei. This consideration sug(mixed melting point) with the I-menthoxyacetic gested that the remarkable stability of the new ester (m. p. 172-174') of natural equilenin. ene-diols might be shared by their vinylogs deDEPARTMENT OF CHEMISTRY W. E. BACHMANNrived from ketones of the types RCO(CH=CH),UNIVERSITY OF MICHIGAN WAYNECOLE ANN ARBOR, MICHIGAN A. L. WILDS COR and RCO(CeH&COR. Evidence of this RECEIVED MARCH28, 1939 already has been brought forward by Lutz and R e ~ e l e y who , ~ report the existence in solution of an ene-diol obtained by the reduction of 1,2-di1,Z-DIARYLACETYLENE GLYCOLS. A NEW TYPE (2,4,6-trimethylbenzoyl)-ethylene. OF_ENE-DIOL A detailed report of our work will be presented Sir: in the near future. The isolation of the dienol I in solid form' sug(3) See Barnes and Green, ibid., 60, 1549 (1938). (4) Paper presented at the Baltimore meeting of the American gested that an ene-diol such as 1,2-dimesitylacetylene glycol (11), being more highly conjugated, Chemical Society, April 4, 1939. OH
REYNOLD C. FUSON UNIVERSITY OF ILLINOIS URBANA, ILLINOIS JOSEPHCORSE RECEIVED MARCH23, 1939
OH
I
I
(CHI)~C~H~C=CCH~C=CC~H~(CH~)~
I
1
CHs CHa I
PANTOTHENIC ACID AND THE FILTRATE (CHICK ANTI-DERMATITIS) FACTOR
Sir:
OH OH
I
I
(CHa)sC6H*C=CC6H1(CH3)s
I1
might possess still greater stability. This has proved to be true. The ene-diol is formed by the action of the binary mixture, Mg Mg12,2 on dimesityl diketone or 2,4,6-trimethylbenzoyl chloride.
+
(1) Fuson, Ross and McReever, THISJOURNAL, 61, 414 (1939) (2) Gomberg and Bachmann,
