KEARRANGEMENT PRODUCT OF HEXA-~-BUTYI,ETHYNYLETHANE 1351
July, 1937
[CONTRIBUTION FROM
THE
CHEMICAL LABORATORY OF THE UNIVERSITY O F ILLINOIS]
Resrrangements of Polyynes. X' Rearrangement Product of Hexa-t-butylethynylethane BY WILLIAM J. SPARKS, W. J. PEPPELAND C. S. MARVEL Hexa - t - butylethynylethane (I) when heated in alcoholic solution rearranges t o an isomeric hydrocarbon, for which no structure has been suggested previously. In view of the work of Farley and Marvel,3 which showed that related acetylenic ethanes rearranged to diallenes, i t is now suggested that the rearrangement of hexa-tbutylethynylethane likewise gives a diallene derivative (11). [(CHa)aC-C~C]aCC[C~C-C(CHs)s]s
---f
I (CHs)sC-C=C=C< (CHJaC-
=C=C
[CrC-C(CHs)s]
< [ C=C-C(
z
CHa)s]z
I1
The following facts support this structure : (1) The hydrocarbon combines with bromine or chlorine t o give a crystalline dibromide or dichloride in practically theoretical yields. Further introduction of chlorine or bromine leads to amorphous products. The dibromide reacts with alkali t o regenerate the hydrocarbon. If addition of bromine takes place a t the ends of the conjugated system in the diallene (11) to give a molecule of structure 111, the compound would be expected to react as this one does. Br
1
(CH3)aC -C--C=C
