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Diastereoselective Synthesis of β 2 ‐Amino Acids
Author(s) -
Ponsinet Rachel,
Chassaing Gérard,
Vaissermann Jacqueline,
Lavielle Solange
Publication year - 2000
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/(sici)1099-0690(200001)2000:1<83::aid-ejoc83>3.0.co;2-2
Subject(s) - alkylation , chemistry , amino acid , enantiomer , enantioselective synthesis , organic chemistry , stereochemistry , catalysis , biochemistry
As part of an ongoing project concerning the synthesis of nonnatural amino acids, we have now developed a general strategy for the preparation of β 2 ‐amino acids (or 2‐aminocarboxylic acid derivatives). Our procedure involves the synthesis of the sultam β‐alaninate precursor 5 whose alkylation led with high yields and excellent diastereoselectivity to the precursor of β 2 ‐homophenylalanine, β 2 ‐homoalanine, and β 2 ‐homoleucine. Subsequent deprotection and Boc‐protection yielded the expected β 2 ‐amino acids. X‐ray analysis of the alkylation product established that (−)‐sultam yielded ( R )‐β 2 ‐amino acids, conversely (+)‐sultam yielded the enantiomer. The topicity of this alkylation is in agreement with the alkylation of Oppolzer's precursor for the synthesis of α‐amino acids and opposite to that observed for gem‐dialkylation.