１‐クロロビニルトリルスルホキシドへの求核剤の共役付加反応を活用する新規有機合成法

Abstract

1-Chlorovinyl p-tolyl sulfoxides, including optically active form, were easily synthesized from carbonyl compounds and chloromethyl p-tolyl sulfoxide in high overall yields. Treatment of the 1-chlorovinyl p-tolyl sulfoxides with cyanomethyllithium gave cyclopentadienyl enaminonitriles in high yields with three consecutive C-C bond-formation. By this method 4, 4-disubstituted 2-cyclopentenones, including optically active form, were synthesized. Asymmetric synthesis of (+) -α-cuparenone was realized by using this method. When cyclic ketones were used in this method, spiro [4.n] alkenones were synthesized in high overall yields. Starting from cyclobutanones, a new synthesis of bicyclo [3.3.0] oct-1-en-3-ones was realized. A new route to fully substituted cyanoallenes was also developed. Reaction of the vinylsulfoxides with N-lithio arylamines was found to give aminoaldehydes, from which α-quaternary α-amino acid derivatives were synthesized. Conjugate addition of lithium ester enolates and lithium amide enolates gave the adducts in high yields with very high 1, 2-, 1, 3- and 1, 4-asymmetric induction from the sulfur chiral center. A new synthesis of optically active carboxylic acids and γ-lactones having a tertiary or a quaternary carbon stereogenic center was realized. A novel method for asymmetric synthesis of both enantiomers of α-substituted carboxylic acid derivatives was also developed by this synthetic method.