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1. WO1999002535 - FABRICATION D'ETHERS TRIALKYLSILYL D'HALOHYDRINE OPTIQUEMENT ACTIVE

Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique

[ EN ]

We claim:
1. A process for the manufacture of optically active compounds comprising:
reacting a meso-epoxide with azidotrimethylsilane and a compound of the formula R'X, where R' is an optionally substituted hydrocarbyl and X is selected from the group consisting of Cl, Br and I;
to produce a compound ofthe formula (1)


wherein:
R is optionally substituted hydrocarbyl, or both together can form a πng;
in the presence of a catalytic amount of a catalyst formed from the sequential treatment of hafnium t-butoxide or zirconium t-butoxide with one equivalent of homochiral optically active triisopropanolamine, water and a source of trifluoroacetate ion.
2. The process of Claim 1 , wherein the optically active triisopropanolamine is selected from the group consisting of (S,S,.S)-triisopropanolamine and (7-,R,7?)-triisopropanolamine.
3. The process of Claim 1 wherein R'X is selected from the group consisting of allyl bromide, allyl iodide, and 2,3-dichloro-l-propene.
4. The process of Claim 1 wherein the meso-epoxide is selected from the group consisting of 1,5-cyclooctadiene monoepoxide, cycloheptene oxide, cyclohexadiene monoepoxide, 3,4-epoxy-2,5-dihydrofuran, cyclopentene oxide, cis-2-butene oxide, and trα/w-l,2-epoxy-4-(methoxymethyl)cyclopentane.
5. The process of Claim 1 wherein the compound of Formula (1) exhibits optical activity to the extent of greater than about 50%) enantiomeric excess.
6. The process of Claim 1 wherein the compound of Formula (1) exhibits optical activity to the extent of greater than about 75%> enantiomeric excess.
7. The process of Claim 1 wherein the catalyst is formed from zirconium t-butoxide.