Abstract
In work related to the preparation of simple analogs of picrotoxin1 and trichodermin,2 we wished to prepare quantities of ketones which were α-alkylated from cyclopentanone and α,β-unsaturated cyclohexenones. The usual base catalyzed procedures3,4 fail because of polyalkylations and formation of isomer mixtures which are difficult to separate.5 The use of enanimes is usually an acceptable alternative for saturated ketones but yields for cyclopentanones are low.6 An alternative α-alkylation procedure for α,β-unsaturated ketones has been developed.5 We wished, however, to reexamine base catalyzed alkylations in the hope of finding a convenient procedure for accomplishing the desired alkylations in larger scale. Systematic investigations of solvents, bases and reaction temperatures were undertaken.