157982-63-3Relevant academic research and scientific papers
Decarbonylation of α-tertiary amino acids application to the synthesis of polyhydroxylated indolizidines from D,L-pipecolic acid
Martin-Lopez, Maria J.,Rodriguez, Rosa,Bermejo, Francisco
, p. 11623 - 11636 (1998)
The decarbonylation of the bicyclic α-tertiary carboxamido acid 11 led to the enamide 12, easily transformed into the indolizidine alkaloid 8,8a- trans-8-hydroxy-indolizidine 14. Likewise, the same process applied to the α-substituted pipecolic acid derivative 5 led to the unsaturated ester 6 which was easily transformed either into δ-coniceine 9 or to 14. The thermal fragmentation of the acyl derivative 22 led to the enamide 24 which has been transformed into (±)-swainsonine 26.
DPPA-promoted decarbonylation of a N-Cbz-(D,L)-pipecolinic acid derivative: An easy entry to [4.5]spirolactams and [4.5]spirolactones. Total synthesis of (±)-δ-coniceine
Martin-Lopez,Bermejo-Gonzalez
, p. 4235 - 4238 (2007/10/02)
The synthesis of 6-benzyloxycarbonyl-1-oxa-6-azaspiro[4.5]decane 2-one 7a and 6-benzyloxycarbonyl-1,6-diazaspiro[4.5]decane-2-one 7b from (D,L)-pipecolinic acid is described. The extremely clean decarboxylation of the α-substituted amino acid 9d promoted by diphenylphosphorazidate (DDPA) is the key step of our strategy. The total synthesis of (±)-δ-coniceine (16) from the enamine ester 10a has been succesfully achieved.
