Synthesis of side-chain homologated analogs of 1,25-dihydroxycholecalciferol and 1,25-dihydroxyergocalciferol.
A novel synthesis of side-chain homologated analogs of vitamin D isomers has been described. The synthesis allows for the insertion of the double bond into the C-24 position of the side chain. The key synthetic step involves the coupling of a new C24-vitamin D synthon with the respective side-chain fragment. The method is illustrated by the preparation of (24E)-24,24a-dehydro-24,24-dihomo-1,25-dihydroxycholecalcife rol (1) and (24b R)- and (24b S)-24,24-dihomo-1,25-dihydroxyergocalciferols (2 and 3). Trans geometry of the newly formed double bond in the side chain was confirmed by high field nuclear magnetic resonance spectra.
Institute of Pharmaceutical Industry, Warszawa, Poland.
M
M
Chodynski
A
A
Kutner
D002117:Calcitriol / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D004872:Ergocalciferols / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure
D004872:Ergocalciferols; C003564:1,25-dihydroxyergocalciferol; D002117:Calcitriol