Leustroducsin B was synthesized via a convergent route based on division of the leustroducsin molecule into three segments A, B, and C. Two coupling reactions (Julia coupling reaction and Nozaki-Hiyama-Kishi (NHK) reaction) were employed for coupling of segments A and 13: segment A, for the Julia coupling reaction was prepared by a combination of Sharpless asymmetric epoxidation and an epoxide-cleavage reaction with an organoaluminum reagent, while segment A, for the NHK reaction was synthesized from optically active alcohol that had previously been prepared by lipase-catalyzed kinetic resolution. Segment B, whose structure was modified with some functional groups, was synthesized from (R)-malic acid by a combination of Wittig reaction and Sharpless asymmetric dihydroxylation, and segment C, containing a cyclohexane moiety, was prepared by asymmetric Diels-Alder reaction. Segment B was first coupled with segment A, via the Julia coupling reaction, but the yield was low due to unexpected epimerization. The NHK reaction of segment A2 proceeded to give the coupling product in good yield. This product was coupled with segment C via Wittig and Stille coupling reactions, and finally, phosphorylation was carried out by partial hydrolysis of a cyclic phosphate to give leustroducsin B.
METHOD FOR THE PREPARATION OF ENANTIOMER FORMS OF CIS-CONFIGURED 3-HYDROXYCYCLOHEXANE CARBOXYLIC ACID DERIVATIVES USING HYDROLASES
申请人:Holla Wolfgang
公开号:US20070197788A1
公开(公告)日:2007-08-23
The present invention relates to a process for preparing chiral non-racemic cis-configured cyclohexanols or cyclohexanol derivatives of the formula (I)
Cis-configured hydroxyl-cyclohexane carboxylic acid derivatives of formula (I) are central building blocks or immediate precursors for the medicinally active compounds which allow a therapeutic modulation of the lipid and/or carbohydrate metabolism and are thus suitable for preventing and/or treating type II diabetes, hyperglycemia and artherosclerosis. The cis-configured hydroxyl-cyclohexane carboxylic acid derivatives of formula (I) are central building blocks or immediate precursors for the medicinally active compounds described in the prior art.
challenging intramolecular hydroacyloxylation reaction. Both HFIP and an internal carboxy group have been proven to be crucial for the successful implementation of this transformation; these are proposed to assist the formation and stabilization of the key cationic intermediate via hydrogen-bondinginteractions with perrhenate anion (ReO4–).
该出版物描述了 Re 2 O 7在六氟异丙醇 (HFIP) 中的应用,用于活化惰性和电子失活的烯烃,以促进具有挑战性的分子内加氢酰氧基化反应。HFIP 和内部羧基均已被证明对于成功实施这一转变至关重要;这些被提议通过与高铼酸盐阴离子 (ReO 4 – )的氢键相互作用来帮助关键阳离子中间体的形成和稳定。
Highly Enantioselective Catalytic Lactonization at Nonactivated Primary and Secondary <i>γ</i>-C–H Bonds
Chiral oxygenated aliphatic moieties are recurrent in biological and pharmaceutically relevant molecules and constitute one of the most versatile types of functionalities for further elaboration. Herein we report a protocol for straightforward and general access to chiral γ-lactones via enantioselective oxidation of strong nonactivated primary and secondary C(sp3)–H bonds in readily available carboxylic
ANTIARRHYTHMIC DRUG, ATRIAL FIBRILLATION INHIBITOR, MODEL OF SUSTAINED ATRIAL FIBRILLATION AND METHOD FOR PRODUCING SAME, AND METHOD FOR SCREENING ATRIAL FIBRILLATION INHIBITOR
申请人:Toho University
公开号:EP2702990A1
公开(公告)日:2014-03-05
An atrial fibrillation inhibitor, including: a compound expressed by one of the following Structural Formulas (I) to (VI) or a pharmacologically acceptable salt thereof, wherein the atrial fibrillation inhibitor inhibits atrial fibrillation:
where in the Structural Formula (III), Gluc refers to glucuronic acid.