NEW FUNCTIONAL ALLYLIC LITHIUM REAGENTS: GEM-DIALKOXYALLYLLITHIUM REAGENTS: A USEFUL ROUTE TO β-SILYL- AND β-STANNYLPROPIONATE ESTERS

Article abstract of DOI:10.1016/S0022-328X(00)90330-9

The reaction of sec-butyllithium with acrolein dialkyl acetals in THF or in THF/Et2O/pentane at -95 deg C results in formation of gem-dialkoxyallyllithium reagents, Li.These react with organosilicon and organotin chlorides to give ketene acetals, R3SiCH2CH=C(OR)2 and R3SnCH2CH=C(OR)2.The acid hydrolysis of these products produces β-substituted propionic acid esters, R3SiCH2CH2CO2R and R3SnCH2CH2CO2R.Reactions of these lithium reagents with allyl bromide gave esters of 5-hexenoic acid, CH2=CH(CH2)3CO2R (R=Me, Et).