FORMATION OF ALPHA-DIALKYLAMINO ALKYLLITHIUM INTERMEDIATES IN THE REACTION OF N,N-DIALKYLAMIDES WITH PHME2SILI FOLLOWED BY A 2ND LITHIUM REAGENT, AND THEIR ALKYLATION, FRAGMENTATION, CYCLIZATION AND REARRANGEMENT BY PROTON-TRANSFER

Tertiary amides (RCONMe2) react with PhMe2SiLi, followed by a second l ithium reagent NuLi, to give alpha-dialkylamino alkyllithium intermedi ates R(Me2N)CLiNu that undergo protonation 2 --> 3, alkylation 2a --> 3ab, beta-elimination 5 --> 6, intramolecular attack on an isolated do uble bond 9 --> 10, intramolecular proton transfer 12, 17 and 22 (arro ws), and fragmentation 28 and 34 (arrows), depending upon the structur es of the various components R and Nu.