Aiming for a catalytic asymmetric access to these natural products, we establish the asymmetric syntheses of the natural isoflavonoids (в€’)-variabilin, (в€’)-homopterocarpin, (в€’)-medicarpin, (в€’)-3,9-dihydroxypterocarpan, and (в€’)-vestitol by means of an asymmetric transfer hydrogenation (ATH) reaction. Especially the 6a-hydroxypterocarpans glyceollin I and glyceollin II, which may be isolated from stressed soy plants, possess a broad spectrum of bioactivities such as anticancer activity and beneficial contributions against western diseases by anti-oxidative and anti-cholesterolemic effects. 2020, 11, 3091.ДЄbstract: Phytoalexins have attracted much attention due to their health-promoting effects and their vital role in plant health during the last years. 'Asymmetric one-pot transformation of isoflavones to pterocarpans and its application in phytoalexin synthesis' Structures of 6aвЂ“c were further proved by alternative synthesis of 6a. All structures were elucidated by spectral and elemental analyses. High yields, short reaction time, easy workup, inexpensive, and reusability of the catalyst are advantages of this method. 2021, 41, 1472-1482.ДЄbstract: Grinding a mixture of 6-aminopyrimidine-2,4(1 H,3 H)-dione 1a or 6-amino-2-thioxo-2,3-dihydropyrimidine-4(1 H)-one 1b or ethyl 7-amino-5-oxo-1-aryl-1,5-dihydro-triazolopyrimidine-3-carboxylate derivatives 5aвЂ“c with 1,2-diphenylethanone 2 and aromatic aldehydes 3aвЂ“j in the presence of aluminate sulfonic acid nanoparticles (ASA NPs) in a one pot solvent-free conditions, afforded the pyridopyrimidinone derivatives 4aвЂ“o and ethyl 5-oxo-1-aryl-6,7,8-triphenyl-1,5,6,9-tetrahydropyridotriazolopyrimidine-3-carboxylate derivatives 6aвЂ“c, respectively. 'One-Pot, Three-Component Synthesis of PyridoPyrimidinones Using Aluminate Sulfonic Acid Nanocatalyst under Grinding Technique'ДЇ. Masking of the Оі-lactone as an acetal allowed for an efficient completion of the synthesis through late-stage double carbonyl olefination. The enantiopure acyclic metathesis substrate was readily available by an asymmetric anti aldol reaction. A triple hydroboration/oxidation of the resultant conjugated triene installed three out of four stereogenic centers of the target in a single step. 2021, 23, 1344-1348.ДЄbstract: The hydroazulene core of the bioactive sesquiterpenoid (в€’)-dehydrocostus lactone was generated by domino enediyne metathesis. 'Enantioselective Total Synthesis of the Guaianolide (в€’)-Dehydrocostus Lactone by Enediyne Metathesis'ДЇ. Furthermore, an alternative intramolecular Diels-Alder strategy employing a 2-bromo-1,3-diene moiety was investigated. Overall, (в€’)-salvinorin A was synthesized in only 16 steps starting from 3-furaldehyde with 1.4% total yield. A chemoselective Mitsunobu inversion of a syn 1,2-diol allowed for further streamlining of the original reaction sequence by two steps. As for our previous synthesis of racemic salvinorin A, two intramolecular Diels-Alder reactions were applied to generate the tricyclic core. The stereogenic center at C-12 was installed by catalytic asymmetric propargylation with excellent enantioselectivity, and the remaining six stereogenic centers were set up highly diastereoselectively under substrate control. 2021, 27, 7968-7973.ДЄbstract: A concise enantioselective total synthesis of the neoclerodane diterpene (в€’)-salvinorin A is reported. 'A Protecting-Group-Free Synthesis of (в€’)-Salvinorin A' Subsequently, the final steps of this approach were improved by using a double carbonyl olefination at the stage of a masked Оі-butyrolactone, which completed the synthesis in a much more efficient way. First, oxidation to give a diketo-Оі-lactone enabled an enantioselective formal synthesis of the target guaianolide. Multiple hydroboration/oxidation of the resulting hydroazulenes set up three out of four stereogenic centers in a single step.

Highly stereoselective asymmetric anti aldol reactions provided the enantiopure substrates for this key step of our synthesis. Our earlier approach by a domino enediyne metathesis was extended by a domino dienyne metathesis strategy to give access to suitably functionalized hydroazulene cores. 2021, 3579-3586.ДЄbstract: An efficient total synthesis of the sesquiterpenoid (в€’)-dehydrocostus lactone is reported. 'Asymmetric Total Synthesis of (в€’)-Dehydrocostus Lactone by Domino Metathesis'ДЇ.

Metz pes 6 pc