Oct., 1949
2 ’-KETONYDRO1,2-CYCLOPENTENONAPHTHALENRS [CONTRIBUTION FROM THE CHEMISTRY
LABORATORY O F THE
3463
UNIVERSITY O F MICHICAX]
3-Ketohydrophenanthrenes and 2 ’-Ketohydro-1,Z-cyclopentenonaphthalenes BY W, E. BACHMANN AND G. DANA JOHNSON’ l-Tetralone-2-@-propionicacid (11) was prepared from 2-carbomethoxy-1-tetraloneby reaction of its sodio derivative with methyl @-bromopropionate and by cyanoethylation to I followed by hydrolysis and decarboxylation. Reaction of the methyl ester of the acid with zinc and methyl bromoacetate gave the unsaturated acid ester IIIa and not the normal hydroxy ester. The acid ester may have resulted through the intermediate formation of the 8-lactone IV followed by hydrolysis in the isolation process. That the 0 /I
0’,
of a maximum withlog E = 4.28 a t 298 mp in the absorption spectrum indicated conjugation of the double bond with the aromatic ring and with the carbonyl Apparently a shift of the double bond occurs a t some stage of the cyclization process.
1
oy~~2~~z~~ 0
A
