Abstract
The α, β-butenolide ring system is found in a number of physiologically important natural products2 and there has been recent interest in the development of methods of synthesis of compounds of this type.3 It is well known that α, β-unsubstituted butenolides may be prepared by catalytic hydrogenation of γ-hydroxy acetylenic acids.4,5b Recently, an excellent route of γ-hydroxy acetylenic esters which involves the addition of the lithium acetylide salts of propiolic esters to aldehydes5 and ketones6 has become available. We have carried out the addition of ethyl lithiopropiolate (1) to cyclohexanone (2) and 4-t-butylcyclohexanone (3) and wish to report the conversion of these adducts into corresponding β-methyl or β-methyl-α-allyl-α, β-butenolides.