Prethodno priopćenje

Stereocontrolled Total Synthesis of 1a,25-Dihydroxyergocalciferol

Andrew D. Batcho ; Department of Natural Products Chemistry, Hoffman-La Roche Inc., Nutley, Neto Jersey 07110
John F. Serena ; Department of Natural Products Chemistry, Hoffman-La Roche Inc., Nutley, Neto Jersey 07110
Enrico G. Baggiolini ; Department of Natural Products Chemistry, Hoffman-La Roche Inc., Nutley, Neto Jersey 07110
Bernard M. Hennessy ; Department of Natural Products Chemistry, Hoffman-La Roche Inc., Nutley, Neto Jersey 07110
Milan R. Uskoković ; Department of Natural Products Chemistry, Hoffman-La Roche Inc., Nutley, Neto Jersey 07110

Sažetak

A stereocontrolled total synthesis of the vitamin D2metabolite
1a,25-dihydroxyergocalciferol (1), which involves a coupling of
the previously described A ring synthon 2 with the appropriately
functionalized C-D moiety 3, is described. In the key step, stereochemical control is achieved by taking advantage of the thermal reversibility of a [3+ 2]-cyc1oaddition of methyl 0,~-dimethylacrylate
and the C-D C-23 nitrone 4 to effect conversion to the C-24S isoxazolidinecarboxylic acid methyl ester Sa, which is readily transformed by reduction followed by elimination of the nitrone function into the necessary C-D precursor.

Ključne riječi

Hrčak ID:

178061

URI

https://hrcak.srce.hr/178061

Datum izdavanja:

6.3.1986.

Posjeta: 794 *