Generation and synthetic application of metallated methyl isopropenyl ether, a substitute for acetone enolate

Article abstract of DOI:10.1002/cber.19971300107

Methyl isopropenyl ether (1) has been metallated at low temperature with a 1:1 molar mixture of n-BuLi/t-BuOK in THFhexane, and subsequently functionalized with a variety of electrophilic reagents. At temperatures higher than -30°C, the metallated methyl isopropenyl ether (2) decomposes with formation of allene. When the suspension of 2 is allowed to warm up to room temperature in the presence of an additional equivalent of n-BuLi, the intermediary aliene is converted into 1-propynyllithium (2c), which reacts with propyl thiocyanate to give 1-propylthio-1-propyne (4). Some of the functionalization products were subjected to acidic hydrolysis affording the expected methyl ketones. VCH Vcrlagsgescllschaft mbH.