Hetero-Diels–Alder and pyroglutamate approaches to (2S,4R)-2-methylamino-5-hydroxy-4-methylpentanoic acid
作者:James E. Tarver、Kristen M. Terranova、Madeleine M. Joullié
DOI:10.1016/j.tet.2004.08.089
日期:2004.11
protected (2S,4R)-2-methylamino-5-hydroxy-4-methylpentanoic acid, a non-coded amino acid of cyclomarin A, and its diastereomer are reported. A pyroglutamate template was employed in the key diastereoselective alkylation used for introducing the 4-methyl stereochemistry. In addition, the first diastereoselective intramolecular hetero-Diels–Alder of a 2-cyano-1-azadiene with an electron deficient dienophile
作者:Claire M. Moody、Bernard A. Starkmann、Douglas W. Young
DOI:10.1016/s0040-4039(00)73531-3
日期:1994.7
(2S,4S)-5-Fluoroleucine, has been prepared by stereospecific synthesis using (2S)pyroglutamic acid as a chiral template. Protection was required in the synthesis to prevent cyclisation to a proline derivative during the fluorination step.