87 results about "Achirality" patented technology

Described herein are methods of syntheses of phosphorous atom-modified nucleic acids comprising chiral X-phosphonate moieties. The methods described herein provide backbone-modified nucleic acids in high diasteteomeric purity via an asymmetric reaction of an achiral molecule comprising a chemically stable H-phophonate moiety with a nucleoside / nucleotide.

A new class of reagents and method of use of the reagents in the reaction of the reagents with electrophilic compounds. The invention in one embodiment is directed to a method for the formation of an alcohol of the formula (I). The method includes reacting a reagent of the formula (II) with an aldehyde of the formula R10CHO to form the alcohol. X3 is one of O and C(R4)(R5). Each of X1 and X2 is independently O or N—R. Each of Ca and Cb is independently an achiral center, an (S) chiral center or an (R) chiral center. Ra and Rb are (i) each independently C1-10 alkyl, C6-10 aryl or C3-9 heteroaryl, or (ii) taken together to form a C3—C4 alkylene chain which together with Ca and Cb forms a 5-membered or 6-membered aliphatic ring. Rc and Rd are each independently hydrogen, C1-10 alkyl, C6-10 aryl or C3-9 heteroaryl. R is C1-10 alkyl, C6-10 aryl or C3-9 heteroaryl. Each of R1, R2, R3, R4, R5 is independently hydrogen, C1—C10 alkyl, C6-10 aryl, C3-9 heteroaryl, C1-10 alkoxy, C6-10 aryloxy, C1-10 dialkylamino, C1-10 alkyl-C6-10 arylamino, C1-10 diarylamino, or halogen. R6 is halogen, hydrogen, C1-10 alkyl, C6-10 aryl, C3-9 heteroaryl, C1-10 alkoxy, C6-10 aryloxy, C1-10 alkyl-C6-10 arylamino, C1-10 diarylamino, OSO2CF3 or SR. R10 may be C1-10 alkyl, C6-10 aryl, or C3-9 heteroaryl.

It is an object of the present invention to provide a novel method for producing (1R,2S) / (1S,2R)-1-amino-1-alkoxycarbonyl-2-vinylcyclopropane which is useful as a synthetic intermediate of therapeutic agents for hepatitis C and a synthetic intermediate thereof. According to the present invention, when a trans-2-butene derivative having a leaving group at each of the 1- and 4-positions is reacted with a malonic ester in the presence of a base, a specific amount of an alkali metal alkoxide or an alkali metal hydride is used as the base, and further a specific amount of a malonic ester is used to produce a cyclopropane diester, and further, chiral or achiral 1-amino-1-alkoxy-carbonyl-2-vinylcyclopropane and a salt thereof are synthesized using the cyclopropane diester.

The present invention relates to a process for the purification of crude bimatoprost to obtain pure bimatoprost comprising a chromatography, preferably a chromatography using an achiral stationary phase and an eluent comprising an alcohol and an apolar solvent; and crystallization of the product obtained the chromatography to obtain pure bimatoprost.