Cyanotrimethylsilane adds to some ⇌,β-unsaturated ketones in conjugate manner under the catalytic action of Lewis acids such as triethylaluminium, aluminiumchloride, and SnCl2. Hydrolysis of the products gives β-cyano ketones which are identical to the hydrocyanated products of the starting enones. The title silicon reagent reacts with acetals and orthoesters under the catalytic action of SnCI2 or BF3-OEt2
-one). Here, four new results are reported concerning the synthesis of substituted bacteriochlorins. First, a new, scalable route to 1,1-dimethoxy-4-methylpent-3-en-2-one removes a significant previous impediment to the overall route. Second, the new route was employed to gain access to new α,β-unsaturatedketones and corresponding dihydrodipyrrins bearing alternative substituents in place of the dimethoxy
The magnesium enolates, generated by treatment of acyclic (1) and cyclic tertiary amides (4) with a (diisopropylamino)magnesium reagent, reacted efficiently with nitriles (2) to afford the corresponding beta-aminoacrylamides (3) and alpha-(alpha-aminoalkylidene)lactams (5). The formation of alpha-(2-pyrrolidinylidene)lactams (7) from the reactions of N-methyl-2-pyrrolidone and N-methyl-2-piperidone with a gamma-cyanopropyl p-toluenesulfonate (6) is also described.