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.
Chodynski
M
M
Institute of Pharmaceutical Industry, Warszawa, Poland.
Kutner
A
A
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