Allylation and propargylation of chiral cyanopropanoates: an efficient route to long chain alpha-substituted alpha-methyl alpha-amino acids

alpha-Methyllysine and 2-amino-2-methylundecanoic acid, two alpha,alpha-disubstituted unnatural glycines, were synthesized using highly diastereoselective allylation or propargylation of chiral (1S,2R,4R)-10-dicyclohexylsulfamoylisobornyl 2-cyanopropanoate as the key step to introduce the long side chain. Chirality 16:106-111, 2004.