161956-11-2Relevant academic research and scientific papers
Enantioselective Synthesis of α-Branched α-Amino Acids with Bulky Substituents
Studer, Armido,Seebach, Dieter
, p. 217 - 222 (2007/10/02)
Enantiopure 5,5-disubstituted t-butyl 2-t-butyl-3-methyl-4-oxoimidazolidine-1-carboxylates readily available by diastereoselective double alkylation of the parent compound (Boc-BMI) can be converted to α-branched α-amino acids with two bulky substituents (PhCH2/Et, PhCH2/i-Pr, PhCH2/CH2C6H11) in four simple steps: hydrolysis to the amino acid amides, N-benzoylation, cleavage of the amino acid amide group, and debenzoylation (Scheme 3, products 6-10, overall yields >50percent).This procedure constitutes an extension of the scope of amino acid synthesis from (R)- and (S)-Boc-BMI. - Key Words: Amino acids, α-branched/ Highly hindered amides/ Hydrolysis of amino acid amides/ Anchimeric effect/ Phenylalanine, 2-ethyl, 2-i-propyl- and 2-cyclohexylmethyl-
