Synthesis of novel β-dialkylamino-α,β-unsaturated trifluoromethylketones containing cyclobutene fragment and their reactions with organolithium and Grignard reagents

Spiro[3.3]heptane as a Saturated Benzene Bioisostere**

“…Despite the seeming simplicity of the current approach to spiro[3.3]heptanes, the preparation of only four products 1 , [18a] 3 , [16d] 37 , [18b] and 40 [16e] from Scheme 2 was previously reported in the literature by other methods.…”

The general approach for the synthesis of substituted cyclobutenyl- and norbornadienyllithiums containing masked trifluoromethyl group

“…12 Diisopropylamine and chloroethanol were distilled prior to use. Manipulations with organolithiums and organotins were carried out under an argon atmosphere.…”

“…Recently we developed unusual [2þ2]-cycloaddition reactions of 1-trifluoroacetyl-2-halogenoacetylenes with simple alkenes to afford substituted 1-trifluoroacetyl-2-halogeno-cyclobutenes, 11 which appeared to be versatile tools for further transformations including the nucleophilic substitution of halogen atoms. 12,13 The addition of organolithiums and Grignard reagents to the available pyrrolidine derivatives 1aed (Fig. 1) is a simple route for their b-functionalization.…”

“…1) is a simple route for their b-functionalization. 12 Herein we report the generation of novel b-alkenyl organolithiums with protected trifluoroacetyl group using enaminoketones 1aef as the starting compounds.…”