growth of C. fasciculata. Only the compounds containing two adjacent carbon atoms with the Lconfiguration are highly active-namely, biopt e r i r ~ ,I~and V. It is not required that one of these carbon atoms be attached to the pyrazine ring, and the presence of other carbinols, either primary or secondary, is without appreciable effect. The biological significance of this configurational specificity is not understood a t this time. Acknowledgment.-- Thc authors are indebted to Ilk, I;.Brancone and staff for the microanalyses.
This material had a n optical rotation of [ o ~ ] ~ 1-33' (c 0.5, 0.1 N NaOH) compared to the Swiss authors' value of [ C ~ ] ~+29.3 ~ D in 0.1 K'aOH. The amount of the 6-isomer in this material was less than 1% measured by the growth stimulation of C. fasciculata, and after oxidation with permanganate the only major product observed by paper chromatography was 2-amino-4-hydroxypteridine7-carboxylic acicL2S4 I t is of interest to note the relationship between the optical configuration about the asymnietric carbon atoms in the polyhydroxyalkyl side chain of these pteridines and their activity in supporting
~the D
CYCLAZINES. T H E SYNTHESIS OF A NEW CLASS OF AROMATIC COMPOUNDS'
T'III (yellow crystals, 1n.p. 98-99". Found: C, 12; H, 3.27). ;Is evidence for the proposed uctures, it as found that treatment of 5-methy-lpyrrocolinc,? I[ (b.p. 124" a t 34 inm. Found: C, S2.00, H, 7.15, N, 10.93) with n-butyllithiuni and ditiietliylbetizaiiii(1e gat-r: T' (1n.p. 111-1 13'. Fouiid: C , N2.15; H, 5.73) which cyclized to give 1-111, idcritical in all respects with the saniplc pwviously describcd. Finally, repetition of the reaction sequence usiiig j-!i~ethylpyrrocoliric and dimethylformaniide gave VI, which on cyclization yielded the parent cycl[3,2,2]azine, IX (yellow crystals, m.p. G5-GG". Found: C, 84.93; H, 5.30;
Sir: \Ye wish to report the sy-iithesis of a new class of aromatic compounds having the general structure shown by IX, for which we propose the trivial name, cycl[3,2,8J a z i ~ i e . The ~ general procedure employed in these syntheses is illustrated below. a'hen 2-phenyl-.S-metliyl~~yrrocoli1ie, I (imp. 5353.5". Found: C, S7.16; €1, G.O;S), prepared by the Chichibabiii procedure, was irealrd with 12-
IA= 4i
---f
N, 0s:).
\\ /\ /-R'
I
'
I,i .
C€I,-COR, 111, Ri = R? = -CsIIi,
IV,R, = --CGH;; Rt \., R' -H;R: = V I , R, = 1:
=
--I1
-= -H ~
CcIZj
YII, RI l7I1I, K1
P L . 3 R i RITF,K,
=z
A!...-, I
~
I n contrast to the behavior of pyrrocolines, the cyclazines shmT unusual stability toward air, light and heat. Also, they show a complete lack of basicity; the ultraviolet absorption spectrum, characteristic of the system, is unaffected by added acid. These observations are in general accord with the Iircdict-ioi1s of simple rnolecular orhital the o r j->:
K? = --CnIli
-11; G - 2 = -CeI-Ij or K' = -C&; I
