Keiichiro Fukumoto

Bio: Keiichiro Fukumoto is an academic researcher from Tohoku University. The author has contributed to research in topic(s): Total synthesis & Enantioselective synthesis. The author has an hindex of 19, co-authored 184 publication(s) receiving 1278 citation(s).

A concise and enantioselective approach to cyclobutanones by tandem asymmetric epoxidation and enantiospecific ring expansion of cyclopropylidene alcohols. An enantiocontrolled synthesis of (+)-and (-)-α-cuparenones

Abstract: A tandem Katsuli-Sharpless asymmetric epoxidation and enantiospecific ring expansion of 2-alkyl(or 2-aryl)-2-cyclopropylideneethanols (1a-i) afforded chiral 1-alkyl(or 1-aryl)-1-(hydroxymethyl)cyclobutanones (3a-i) in high yields and high enantiomeric excess. These compounds are potentially valuable synthons for the enantioselective creation of the quaternary carbons. Hence, this enabled us to accomplish a concise and enantioselective total synthesis of both (+)- and (-)-α-cuparenones

Studies on the syntheses of heterocyclic compounds. 675. A facile regiospecific and stereocontrolled synthesis of a diterpene alkaloid intermediate from benzocyclobutenes

Abstract: Das aus der Cyanpropionsaure (I) erhaltliche Benzocyclobuten (II) reagiert mit dem Jodid (III) (mittels ublicher Methoden aus α-Methylacetessigsauremethylester erhaltlich) zu dem Kondensationsprodukt (IV), das bei Thermolyse regiospezifisch und stereoselektiv in das Octalin (V) ubergeht.

Asymmetric total synthesis of(–)-protoemetinol,(–)-protoemetine,(–)-emetine, and (–)-tubulosine by highly stereocontrolled radical cyclisations

Abstract: Both enantiomers of the menthyl half-esters (10) and (23) of ethylmalonic acid were converted into(+)-(4S,5R)-4-(2-benzyloxyethyl)-5-ethyl-3,4,5,6-tetrahydro-2-pyrone (18). A mixture of the trans-(18) and cis-lactones (19) in a ratio of ca. 4 : 1 was prepared by way of radical cyclisation of the (E)-α,β-unsaturated esters (16), while the former (18) was synthesised with high stereoselection by the cyclisation of the (Z)-esters (26). The lactone (18) was enantioselectively transformed into (–)-protoemetimol (5) and (–)-protoemetine (4), correlated to (–)-emetine (1) and (–)-tubulosine (3).

Quinoline, quinazoline and acridone alkaloids

Abstract: Covering: July 2005 to June 2006. Previous review: Nat. Prod. Rep., 2007, 24, 223–246 This review covers the isolation, structure determination, synthesis and biological activity of quinoline, quinazoline and acridone alkaloids from plant, microbial and animal sources; 115 references are cited.

The Diels--Alder reaction in total synthesis.

Abstract: The Diels-Alder reaction has both enabled and shaped the art and science of total synthesis over the last few decades to an extent which, arguably, has yet to be eclipsed by any other transformation in the current synthetic repertoire. With myriad applications of this magnificent pericyclic reaction, often as a crucial element in elegant and programmed cascade sequences facilitating complex molecule construction, the Diels-Alder cycloaddition has afforded numerous and unparalleled solutions to a diverse range of synthetic puzzles provided by nature in the form of natural products. In celebration of the 100th anniversary of Alder's birth, selected examples of the awesome power of the reaction he helped to discover are discussed in this review in the context of total synthesis to illustrate its overall versatility and underscore its vast potential which has yet to be fully realized.

Domino Reactions in Organic Synthesis

Abstract: Introduction Cationic domino reactions Anionic domino reactions Radical domino reactions Pericyclic domino reactions Photochemically induced domino processes Transition metal catalysis Domino reactions initiated by oxidation or reduction Enzymes in domino reactions Multicomponent reactions Special techniques in domino reactions