Studies on the synthesis of corrins and related ligands. An alternate synthesis of “semicorrin E”

✍ Scribed by Robert V. Stevens; Edward B. Reid

• Book ID: 104224282
• Publisher: Elsevier Science
• Year: 1975
• Tongue: French
• Weight: 171 KB
• Volume: 16
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)91146-8

✦ Synopsis

As part of a program whose ultimate goal 1s the total synthesis of vltamln B-12,' we have recently developed new methodology for construction of the macrocycllc corphln (1)' and corrin (3)3 llgands. A key internledlate in these studies was the tnlsoxazole 2 which serves as a latent synthon for three of the vlnylogous amldlne chromophores common to each of these macrocycles However, as noted prevlously,4 all of the structural features of these llgands can also be Incorporated into the isomerlc tnlsoxazole 4 which, In prlnclple, can be assembled from the nltnle oxides and terminal acetylenes shown In diagram 5 It should be noted that all four subunits (5A-D) are, in pnnciple, derivatives of acetylenlc nltnle ."__.-5i. The possibility of constructing both macrocycllc llgands from this single starting material was sufflclently lntnqulng to prompt us to test the chemistry required to achieve this goal 3 3 3 4193