de Silva SO,
Reed JN,
Snieckus V.
*
University of Waterloo, Canada
Directed Lithiation of
N,
N-Diethylbenzamides. Regiospecific Synthesis of Contiguously Tri- and Tetra-Substituted
Alkoxybenzenes.
Tetrahedron Lett. 1978;
51: 5099-5102
DOI:
10.1016/S0040-4039(01)85822-6
Key words
lithiation -
ortho-functionalization - benzamides
Significance
Snieckus and co-workers reported a regiospecific ortho-lithiation of various N,N-diethylbenzamides using sec-BuLi and TMEDA in THF. The formed lithiated species were trapped with a range of
electrophiles and the desired products were obtained in moderate to excellent yield.
Comment
The authors demonstrated the utility of this methodology for the synthesis of naturally
occurring alkaloids. Thus, a formylated product was converted by successive reduction
and cyclization into meconine in 90% yield. Subsequent hydrolysis furnished opianic
acid in 50% yield.
