The interaction between a nonionic surfactant and acid dyes studied by measurements of cloud point

In order to clarify the interaction behaviors between a nonionic surfactant (S) and an acid dye (D), the cloud points (CP) were measured for the solution containing S and D with increasing amounts of electrolytes and are plotted as a function of the electrolyte concentration. A clear transition point Z was observed in the CP curve. The value of C^z, the electrolyte concentration at Z, depends upon the valence number of the cation of the added electrolyte rather than that of the anion. While the value of T^z, the temperature at Z, is independent of the kind of electrolyte and dye, but depends on the molar ratio of S to D in the solution. On the basis of the phase rule, the existence of Z was interpreted in terms of a triple point of three types of mixed micelles which are formed of S and D.     

CP-odd anomalous W-boson couplings from supersymmetry

The supersymmetric standard model contains a new -violating phase in the mass matrices for charginos and neutralinos, which could induce -odd anomalous couplings for the and vertices at the one-loop level. We study these couplings, paying attention to the model-parameter and dependencies. It is shown that the -odd form factors could have values of order , which are much larger than those predicted by the standard model. We also discuss the possibility of examining these form factors in experiments. Received: 6 October 1997 / Published online: 26 February 1998     

Catalytic asymmetric epoxidation of alpha,beta-unsaturated amides: efficient synthesis of beta-aryl alpha-hydroxy amides using a one-pot tandem catalytic asymmetric epoxidation-Pd-catalyzed epoxide opening process

The catalytic asymmetric epoxidation of alpha,beta-unsaturated amides using Sm-BINOL-Ph3As=O complex was succeeded. Using 5-10 mol % of the asymmetric catalyst, a variety of amides were epoxidized efficiently, yielding the corresponding alpha,beta-epoxy amides in up to 99% yield and in more than 99% ee. Moreover, the novel one-pot tandem process, one-pot tandem catalytic asymmetric epoxidation-Pd-catalyzed epoxide opening process, was developed. This method was successfully utilized for the efficient synthesis of beta-aryl alpha-hydroxy amides, including beta-aryllactyl-leucine methyl esters. Interestingly, it was found that beneficial modifications on the Pd catalyst were achieved by the constituents of the first epoxidation, producing a more suitable catalyst for the Pd-catalyzed epoxide opening reaction in terms of chemoselectivity.     

Silyl-enolization-asymmetric Claisen rearrangement of 2-allyloxyindolin-3-one: enantioselective total synthesis of 3a-hydroxypyrrolo[2,3-b]indoline alkaloid alline

Asymmetric Claisen rearrangement triggered by silyl-enolization of 2-(1′-nonel-3′-yloxy)indolin-3-ones was performed in order to prepare 3-(2′-nonenyl)-3-hydroxyindolin-2-ones. Total synthesis of 3-hydroxypyrrolo[2,3-b]indoline alkaloid, (+)-alline was achieved by transformation of the allylic moiety of 3-(2′-nonenyl)-3-hydroxyindolin-2-one to amine followed by reductive cyclization.     

Catalytic cyclopropanation of alkenes via (2-furyl)carbene complexes from 1-benzoyl-cis-1-buten-3-yne with transition metal compounds

The reaction of alkenes with conjugated ene-yne-ketones, such as 1-benzoyl-2-ethynylcycloalkenes, with a catalytic amount of Cr(CO)(5)(THF) gave 5-phenyl-2-furylcyclopropane derivatives in good yields. The key intermediate of this cyclopropanation is a (2-furyl)carbene complex generated by a nucleophilic attack of carbonyl oxygen to an internal alkyne carbon in pi-alkyne complex or sigma-vinyl cationic complex. A wide range of late transition metal compounds, such as [RuCl(2)(CO)(3)](2), [RhCl(cod)](2), [Rh(OAc)(2)](2), PdCl(2), and PtCl(2), also catalyzes the cyclopropanation of alkenes with ene-yne-ketones effectively. When the reactions were carried out with dienes as a carbene acceptor, the more substituted or more electron-rich alkene moiety was selectively cyclopropanated with the (2-furyl)carbenoid intermediate.     

A stereocontrolled total synthesis of 2β,3β,20β-triacetoxy-5α-pregnan-6-one — A total synthesis of 20-hydroxyecdysone

The stereoselective total synthesis of 2β,3β,20β-triacetoxy-5α-pregnan-6-one ($\text{2}$) via acetylene-cation cyclization of $\text{7}$, which was readily derived from the D-ring aromatic steroid $\text{3}$, is described and this constitutes a total synthesis of 20-hydroxyecdysone ($\text{1}$).     

Water-soluble constituents of cumin: monoterpenoid glucosides

From the water-soluble portion of the methanol extract of cumin (fruit of Cuminum cyminum L.), which has been used as a spice and medicine since antiquity, sixteen monoterpenoid glucosides, including twelve new compounds, were isolated. Their structures were clarified by spectral investigation.     

A novel modified baylis-hillman reaction of propiolate

A new reaction of propiolates and aldehydes mediated by DABCO analogous to the Baylis-Hillman reaction is described. This reaction provided novel beta-functionalized Baylis-Hillman products and a new methodology for the generation of alkylidene carbene species.