Diethyl 3-methylcyclopent-3-ene-1,1-dicarboxylate → 3-Methyl-cyclopent-3-enecarboxylic acid
Reaction equation
C12CC(CC1)CCO2.[CH3:9][C:10]1[CH2:14][C:13](C(OCC)=O)([C:15]([O:17]CC)=[O:16])[CH2:12][CH:11]=1>>[CH3:9][C:10]1[CH2:14][CH:13]([C:15]([OH:17])=[O:16])[CH2:12][CH:11]=1Participants
3
Procedure
When m is 1, n is 2 and p is 1, the ring system is a 2-oxabicyclo[3.2.1]octane, another subclass of this invention. For example, compound XIIp ##STR26## in which R2, R5 and R6 are methyl, can be prepared by saponification and decarboxylation of diethyl 1-methylcyclopent-1-ene-4,4-dicarboxylate, prepared by the procedure of E. E. Schweiger and G. J. O'Neill, J. Org. Chem., 30, 2082 (1965), to provide 1-methylcyclopent-1-ene-4-carboxylic acid. The resulting carboxylic acid is homologated in the manner proscribed for the compounds XIp, and subsequently treated similarly to the acid of subclass IX.
Workup
- customprepared by the procedure of E