Stereocontrolled preparation of chiral secondary α-methylene γ-lactams by addition of organozinc reagents derived from 2-(bromomethy])acrylates to imines using β-aminoalcohols as chiral auxiliaries.
摘要:
Stereocontrolled addition of isolated organozinc reagents 1, prepared from 2-(bromomethyl)acrylates to imines, can be achieved with d.e. approximately 100% using beta-amino alcohols as chiral auxiliaries. High yields of pure R or S secondary alpha-methylene gamma-lactams can be prepared after a three step elimination of the chiral auxiliary (chloration, dehydrochloration of the resulting beta-chloroamine, acid hydrolysis of enamide).
Stereocontrolled preparation of chiral secondary α-methylene γ-lactams by addition of organozinc reagents derived from 2-(bromomethy])acrylates to imines using β-aminoalcohols as chiral auxiliaries.
摘要:
Stereocontrolled addition of isolated organozinc reagents 1, prepared from 2-(bromomethyl)acrylates to imines, can be achieved with d.e. approximately 100% using beta-amino alcohols as chiral auxiliaries. High yields of pure R or S secondary alpha-methylene gamma-lactams can be prepared after a three step elimination of the chiral auxiliary (chloration, dehydrochloration of the resulting beta-chloroamine, acid hydrolysis of enamide).
Diastereoselective radical addition to γ-alkyl-α-methylene-γ-butyrolactams and the synthesis of a chiral pyroglutamic acid derivative
作者:Tomoko Yajima、Eriko Yoshida、Masako Hamano
DOI:10.3762/bjoc.9.161
日期:——
The cis- and trans-stereoselective radical additions to alpha-methylene-gamma-alkyl- gamma-lactams were investigated and the scope and limitation of the reaction were also revealed. This stereoselective radical reaction was used for synthesis of chiral pyroglutamic acid derivatives starting from a commercially available chiral amino acid.