Manabu Node

Binaphthol as a chiral auxiliary. Asymmetrical alkylation of arylacetic acid

Abstract Binaphthyl esters of substituted and unsubstituted phenylacetic acids were alkylated with a high diastereoselectivity.

Regioselective ring opening of unsymmetrical cyclic ethers with the A1C13-NaI-acetonitrile system: Application to hydroxylation of ent-kaurene.

Abstract Unsymmetrically substituted 5-membered cyclic ethers were effectively cleaved with the A1C1 3 -NaI-CH 3 CN system at the less hindered carbon atom to afford δ-iodoalcohols. Conversion of ent -kaurene to ent -14α- and ent -12β-hydroxykaurene was achieved through the ring opening of the cyclic ether with the present system as a key step.

Isolation of the diterpenoid teuflin (6-epiteucvin) from Teucrium viscidum var. miquelianum

Abstract The diterpenoid teuflin (6-epiteuevin) has been isolated from Teucrium viscidum var. miquelianum . Its base catalysed epimerization into teucvidin was studied under mild conditions and the pathway is discussed.

General entry to the synthesis of optically active diterpenoids of C-20β series

Abstract (+)-Podocarpic acid ( 2 ) and (+)-lambertic acid ( 3 ) were synthesized from ( S )-(−)-nitroolefin 1a .

Kinetic resolution of lactones by enantioselective protonation of the corresponding carboxylate with a chiral acid

Racemic lactones were optically activated through the hydrolysis with sodium hydroxide followed by the partial neutralization with (IS)-(+)-10-camphorsulfonic acid in ethanol to afford R- or S-isomer with 99 - 38% ee.

THE STRUCTURES OF SPIRAMINES E, F AND G - THE NEW DITERPENE ALKALOIDS FROM SPIRAEA-JAPONICA VAR ACUMINATA FRANCH

Structures of spiramines E (1), F (2) and G (3) were elucidated by chemical and spectroscopic means

A convenient reduction of functionalized polycyclic aromatics into parent hydrocarbons

Abstract Polycyclic aromatics with various functional group (e.g. OH, OR, SR, and halogen) were easily defunctionalized by aluminum chloride and ethanethiol to give parent aromatics in high yields under mild conditions. This reaction proceeds through sulfide as the intermediate, hence it is also useful for the synthesis of sulfides of polycyclic aromatics.

Addition-elimination strategy for asymmetric induction : a chiral sulfoxide as a leaving group

Abstract The reaction of β-nitro-α,β-unsaturated sulfoxide 7 with δ-lactam enolates 11 – 15 afforded 20 – 24, respectively, in good chemical yields with high enantiomeric excesses.

Lewis acid mediated thienium cation diels-alder reaction: A new method for regio- and stereoselective functionalization of 1,3-dienes

Abstract Under the influence of aluminum chloride the β-ethylthionitroolefin results in the formation of the thienium cation, which reacts with a variety of 1,3-dienes in the Diels-Alder sense. The cleavage of the resulting ring provides in one pot the 1,4-functionalized olefins in regio- and stereoselective manner.

Hard acid and soft nucleophile systems. part 12. Regioselective functionalization of 1,3-dienes through the lewis acid mediated thienium cation diels-alder reaction

Abstract Reaction of α-Ethylthio-β-nitroolefins with 1,3-dienes under acidic Diels-Alder conditions afforded Z-olefins through stereoselective 1,4- functionalization.