640769-22-8Relevant academic research and scientific papers
Stereocontrolled synthesis of a Cn-Cn+6 building block for the unnatural enantiomers of important polyol,polyene antibiotics from an epoxy alcohol by a reduction/conjugate addition/hydroxylation sequence
Kramer, Rainer,Brueckner, Reinhard
, p. 6563 - 6583 (2013/11/06)
Epoxy alcohol anti-10, derived from a desymmetrizing Sharpless epoxidation (up to 97a€‰% ee) of divinylcarbinol 9, provided the unsaturated 1,3-diol syn-11 upon treatment with RedAl; syn-11 was converted into the α,β-unsaturated esters (E)- or (Z)-7b in three steps. Cu-promoted 1,4-addition of vinylmagnesium halides to the (E)-ester proceeded with diastereoselectivities of up to 91a€‰% and Cu-catalyzed 1,4-additions with diastereoselectivities of up to 82a€‰%. The potassium enolate of the major vinylation product syn-22b was hydroxylated by the Davis oxaziridine with perfect but unprecedented diastereoselectivity. The resulting hydroxy ester, α,βsyn, β,γsyn-32, furnished the eastern moiety building block 6 of the title compounds in three steps. A CuBr·SMe 2/LiBr/LiSPh-promoted 1,4-addition of vinylmagnesium chloride to a γ-chiral α,β-unsaturated ester, obtained from a Sharpless epoxide, and an ensuing hydroxylation of the C-α position with the Davis oxaziridine has established the stereocenter of the epoxide ring. Copyright
Stereocomplementary desymmetrizations of divinylcarbinols by zirconium(IV)- vs. titanium(IV)-mediated asymmetric epoxidations
Kramer, Rainer,Berkenbusch, Thilo,Brueckner, Reinhard
experimental part, p. 1131 - 1148 (2009/06/17)
Substituted Cs-symmetric penta-1,4-dien-3-ols ("divinylcarbinols") containing cis- or trans-disubstituted C=C bonds were desymmetrized by asymmetric monoepoxidations. Sharpless conditions gave anti-configured monoepoxides. For cis,cis-divinylca
Concise Synthesis of Optically Pure syn-1,3-Diols by Stereoselective Desymmetrization of a Divinylcarbinol
Berkenbusch, Thilo,Brückner, Reinhard
, p. 1813 - 1816 (2007/10/03)
Divinylcarbinols 17 and 18, CS-symmetrical and cis-configured, were desymmetrized by Sharpless' asymmetric epoxidation. This furnished anti-configured monoepoxy alcohols 19 (85% ee) and 20 (94% ee), respectively, or their mirror images (ent-19, 84% ee; en
