ABSTRACT
A novel and unexpected aryne insertion cascade reaction on 2-arylidene-1,3-indandiones via conjugate addition of fluoride followed by formal C-C insertion is developed to afford dibenzo[a,d]cycloheptanoid derivatives in good yields with a single isomer. This reaction represents a rare instance of cyclic enone C-C bond insertion (acyl-alkenylation) in aryne chemistry. Interestingly, 2-arylidene-1,3-indandiones bearing electron rich functional groups provided dibenz[a,c]anthracene-9,14-dione derivatives via [4 + 2] cycloaddition followed by ring expansion.
ABSTRACT
An efficient method for the preparation of kojic acid based α-amino acid derivatives by alkylation of glycinate schiff base with bromokojic acids have been described. Using this method, mono as well as di alkylated kojic acid-amino acid conjugates have been prepared. This is the first synthesis of C-linked kojic acid-amino acid conjugate where kojic acid is directly linked to amino acid through a C-C bond.
Subject(s)
Amino Acids/chemical synthesis , Pyrones/chemistry , Amino Acids/chemistry , Molecular StructureABSTRACT
A new series of isoxazole tethered quinone-amino acid hybrids has been designed and synthesized involving 1,3-dipolar cycloaddition reaction followed by an oxidation reaction using cerium ammonium nitrate (CAN). Using this method, for the first time various isoxazole tethered quinone-phenyl alanine and quinone-alanine hybrids were synthesized from simple commercially available 4-bromobenzyl bromide, propargyl bromide, and 2,5-dimethoxybenzaldehyde in good yield.