Total Synthesis of a CD-Ring: Side-Chain Building Block for Preparing 17-epi-Calcitriol Derivatives from the Hajos–Parrish Dione
摘要:
An efficient synthesis of the key building block for 17-epi-calctriol from the Hajos-Parrish dione involving a sequence of diastereoselective transformation of the azulene core and the side-chain construction is presented.
chiroptical properties of cyclic sulfites utilizing the electronic circular dichroism (CD) and time-dependent density functional theory (TD-DFT). For some of the modelcompounds the study was additionally supported by the X-ray diffraction analysis. A comparison of the experimental and simulated CD spectra gave a reasonable interpretation of the Cotton effects observed in the 200−220 nm spectral range. The
An Expedited Approach to the Vitamin D <i>trans</i>-Hydrindane Building Block from the Hajos Dione
作者:Paweł Chochrek、Jerzy Wicha
DOI:10.1021/ol060775y
日期:2006.6.1
Efficient and operationally simple synthesis of the key trans-hydrindane alcohol building block for the synthesis of calicitriol (1 alpha,25-dihydroxyvitamin D(3)) has been developed. Epoxy alcohol prepared almost quantitatively from the Hajos dione was reduced at the quaternary carbon by the Hutchins procedure (NaBH(3)CN-BF(3)(.)Et(2)O). The diol was selectively deoxygenized either using the Barton-McCombie reaction (with Bu(3)SnH-AIBN) or via the respective iodohydrine (with LiAlH(4)).