58006-28-3Relevant academic research and scientific papers
Novel versatile approach to an enantiopure 19-nor, des-C,D vitamin D3 derivative
Hilpert, Hans,Wirz, Beat
, p. 681 - 694 (2007/10/03)
A short and efficient de novo route to the des-C,D vitamin D3 derivative 3 (Ro 65-2299), a potential antipsoriatic, has been developed. This route features an assembly strategy so far unexplored in vitamin D chemistry involving a modified Julia olefination of the A-ring ketone 30 and the 2-benzothiazolyl sulfone 60. Construction of the A-ring building block was accomplished by an efficient three-step route starting from the meso trans-1,3,5-cyclohexane triol (26), which was desymmetrized by a highly selective enzymatic mono-hydrolysis of the corresponding triacetate 27 followed by oxidation of the alcohol 29 to give the homochiral diacetoxy ketone 30 (ee=99.5%) in 83% overall yield. Furthermore, we found efficient and practical syntheses of the 5-acetoxy-2-cyclohexenone (31) and its enantiomer 32, both new building blocks useful for natural product synthesis.
Multiselective enzymatic reactions for the synthesis of protected homochiral cis- and trans-1,3,5-cyclohexanetriols
Wirz, Beat,Iding, Hans,Hilpert, Hans
, p. 4171 - 4178 (2007/10/03)
For the synthesis of the potentially antipsoriatic vitamin D derivative 3 (Ro 65-2299) an efficient and multiselective enzymatic step had been developed in which the easily accessible trans-1,3,5-triacetoxy-cyclohexane 5 was selectively monohydrolyzed in the presence of the cis-isomer 8 to give (1R,3R)-1,3-diacetoxy-5-hydroxy-cyclohexane 6 in high enantiomeric excess (>99%) and yield (84%). Furthermore, for the synthesis of the enantiomer of 3, a simple and efficient enzymatic procedure for the asymmetric acetylation of cis-1,5-dihydroxy-3-(tert-butyldimethylsilanoxy)-cyclohexane 10 in an anhydrous organic solvent providing (1R,3S,5S)-1-acetoxy-3-hydroxy-5-(tert-butyldimethylsilanoxy)-cyclohexane 11 in >99% ee and quantitative yield is described. Copyright (C) 2000 Elsevier Science Ltd.
