Conjugate addition of lithiated Schöllkopf's bislactim ether to 1E,3E-butadienylphosphonates: Stereocontrolled access to 2,3-anti-4E 2-amino-6-phosphono-4-hexenoic acid derivatives

✍ Scribed by Vicente Ojea; Susana Conde; María Ruiz; Ma Carmen Fernández; JoséMa Quintela

• Book ID: 104257248
• Publisher: Elsevier Science
• Year: 1997
• Tongue: French
• Weight: 310 KB
• Volume: 38
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(97)00888-5

✦ Synopsis

Face-selective 1,6-addition of lithiated SchOllkopf's bislactime ether 5 to 4-substituted, 1,4-or 3,4-disubstituted 1E,3E-butadienylphosphonates 6a-d allows a direct and stereocontrolled access to semi-rigid AP6 analogues, the 2,3-anti-4E 2-amino-6-phosphono-4-hexenoic acid derivatives 4a-c. The relative stereochemistry was assigned from a NMR study of the cyclic derivative 12c. Tenmembered trans-fused chair-boat-like transition states are invoked to rationalize the stereochemical outcome of the addition.