137693-94-8Relevant academic research and scientific papers
Process and intermediates useful to produce vitamin D analogs
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Page column 17, (2010/01/30)
A stereospecific method for accomplishing the below reaction: results in the compound of formula 2 having the same stereochemistry at both carbon 1 and carbon 3 as that in the compound of formula 1. Thus, if carbon 3 is in the R-configuration in the compo
Efficient synthesis of the A-ring phosphine oxide building block useful for 1α,25-dihydroxy vitamin D3 and analogues
Daniewski, Andrzej R.,Garofalo, Lisa M.,Hutchings, Stanley D.,Kabat, Marek M.,Liu, Wen,Okabe, Masami,Radinov, Roumen,Yiannikouros, George P.
, p. 1580 - 1587 (2007/10/03)
The 1α-hydroxy A-ring phosphine oxide 1, a useful building block for vitamin D analogues, was synthesized from (S)-carvone in nine synthetic operations and a single chromatographic purification in 25% overall yield. The synthesis features two novel efficient synthetic transformations: the Criegee rearrangement of α-methoxy hydroperoxyacetate 10 in methanol to obtain directly the desired secondary 3β-alcohol 11 and the highly chemo- and stereoselective isomerization of dieneoxide ester (E)-7 to the 1α-allylic alcohol with an exocyclic double bond (E)-8. Further insight into the selectivity control of the latter rearrangement was obtained from the reactions of (Z)epimeric substrates. The new synthetic approach leading to the 1α-hydroxy epimers complements our previously reported synthesis of the corresponding 1β-epimers, thus producing all stereoisomers of these versatile building blocks efficiently from carvone.
Stereoselective Synthesis of 1α-Hydroxyvitamin D3 A-Ring Synthons by Palladium-Catalyzed Cyclization
Nagasawa, Kazuo,Zako, Yoshiro,Ishihara, Hideki,Shimizu, Isao
, p. 4937 - 4940 (2007/10/02)
Palladium-catalyzed cyclization of 8-bromo-2,8-nonadienoates proceeded stereoselectively to give 1α-hydroxyvitamin D3 A-ring synthons in good yields.
