BETA-FUNCTIONALIZED ORGANOLITHIUM COMPOUNDS THROUGH A SULFUR-LITHIUM EXCHANGE

The successive reaction of different beta-hydroxy or beta-amino thioet hers 1a-d with n-butyl-lithium and an excess of lithium powder and a c atalytic amount of DTBB in THF at -78 degrees C leads to the formation of the corresponding beta-functionalised organolithium compounds 2a-d , which by reaction with several electrophiles [D2O, (BuCHO)-C-t, PhCH O, Me2CO, (CH2)(5)CO] at temperatures ranging between -78 and 20 degre es C yields, after hydrolysis with water, the expected functionalised alcohols or amines Saa-de in a regioselective manner. (C) 1997 Elsevie r Science Ltd.