Structure and Reactivity of Xanthocorrinoids. Part III. The first example of a pinacol-type rearrangement in the corrin series
作者:Burghard Grüning、Gerhard Holze、Albert Gossauer、Ludger Ernst
DOI:10.1002/hlca.19850680632
日期:1985.9.25
The transformation of the c-acetic-acid chain of hexamethyl Coα, Coβ-dicyanocobyrinate into an ethyl group (2) as well as the synthesis of the pentadecaalkyl-cobalticorrin 6d from commercial cyanocobalamin are described. On reaction of 2 or 6d with O2 in the presence of ascorbic acid, migration of the CH3 group at C(5) to the vicinal position C(6) takes place concomitantly with the introduction of
Hydrophobic Vitamin B12 Derivatives: Unprecedented Formation of a 7-Membered Lactam
作者:Keith ó Proinsias、Sylwester Kurcoń、Dorota Gryko
DOI:10.1002/ejoc.201101249
日期:2012.1
The synthesis of a new hydrophobic cobalamin derivative through intramolecularaminolysis is described. Under acidic conditions, (CN)2CobIII(10-NH2)7C1-ester formed a seven-membered lactam between the ester and amino groups present at the C8 and C10 positions. Subsequent Boc protection of the NH group enabled ring opening with primary amines, leading to derivatives functionalized at the C8 and C10