Two new approaches to the 25-hydroxy-vitamin D2 side chain
摘要:
Two approaches to the 25-hydroxy-vitamin D2 side chain have been developed based on the solvolysis of cyclopropylcarbinyl precursors. The first involves addition of trimethylcyclopropyllithium reagent 4 to a suitably protected C/D system 9. This reaction leads directly to cyclopropylcarbinols 10a,b which can be solvolyzed to the vitamin D2 side chain directly. The second approach uses an intermediate C/D system with a side chain allylic alcohol. Cyclopropanation of the allylic alcohol using Et2Zn/CH3CHI2 produces the same type of cyclopropylcarbinols 10a,b but in differing isomer ratios. Model studies and stereochemical differences in the two approaches are discussed.
Two new approaches to the 25-hydroxy-vitamin D2 side chain
摘要:
Two approaches to the 25-hydroxy-vitamin D2 side chain have been developed based on the solvolysis of cyclopropylcarbinyl precursors. The first involves addition of trimethylcyclopropyllithium reagent 4 to a suitably protected C/D system 9. This reaction leads directly to cyclopropylcarbinols 10a,b which can be solvolyzed to the vitamin D2 side chain directly. The second approach uses an intermediate C/D system with a side chain allylic alcohol. Cyclopropanation of the allylic alcohol using Et2Zn/CH3CHI2 produces the same type of cyclopropylcarbinols 10a,b but in differing isomer ratios. Model studies and stereochemical differences in the two approaches are discussed.
VITAMIN D RECEPTOR ACTIVATORS AND METHODS OF MAKING
申请人:Von Geldern Thomas W.
公开号:US20090131379A1
公开(公告)日:2009-05-21
The invention relates to compounds that are vitamin D receptor activators, compositions comprising such compounds, methods of using such compounds and compositions, processes for preparing such compounds, and intermediates obtained during such processes.
Two new approaches to the 25-hydroxy-vitamin D2 side chain
作者:Stephen R. Wilson、Andrew E. Davey、Maria E. Guazzaroni
DOI:10.1021/jo00033a021
日期:1992.3
Two approaches to the 25-hydroxy-vitamin D2 side chain have been developed based on the solvolysis of cyclopropylcarbinyl precursors. The first involves addition of trimethylcyclopropyllithium reagent 4 to a suitably protected C/D system 9. This reaction leads directly to cyclopropylcarbinols 10a,b which can be solvolyzed to the vitamin D2 side chain directly. The second approach uses an intermediate C/D system with a side chain allylic alcohol. Cyclopropanation of the allylic alcohol using Et2Zn/CH3CHI2 produces the same type of cyclopropylcarbinols 10a,b but in differing isomer ratios. Model studies and stereochemical differences in the two approaches are discussed.