
TY  - JOUR
A1  - Johns, RB 
A1  - Kriegler, AB 
T1  - Photolytic studies of cyclic unsaturated ketones. I. Irradiation products of 2-Methylcyclobutane-1,3-dione and its ethyl enol ether
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1970
VL  - 23
IS  - 8
SP  - 1635
EP  - 1640
KW  - 
UR  - https://doi.org/10.1071/CH9701635 
N2  - The photochemical rearrangement of 2-methylcyclobutane-1,3-dione and the ethyl ether of its enol (4) have been shown to follow the expected pathway for an &#945;, &#946;-unsaturated cyclobutenone. The enol ether, when irradiated in moist cyclohexane, forms 3-ethoxy-2-methyl-trans-crotonic acid (8) which is photo-isomerized to the cis-isomer (7). This latter isomer is the major product when the solvent is moist diethyl ether. It is suggested that the necessary rotation about a carbon-carbon single bond is solvent-dependent, and occurs in a &#946;,&#947;-unsaturated carboxylic acid formed as a reaction intermediate. 
ER  -

