Total synthesis of gliotoxin,dehydrogliotoxin and hyalodendrin

Two general methods, Method A and Method B in Scheme 19, to synthesize epidithiapiperazinediones, are described. A total synthesis of racemic and optically active gliotoxin (1) and of racemic dehydrogliotoxin (53) was achieved by using Method A, whereas a total synthesis of racemic hyalodendrin (52) was completed by using Method B.     

Two dimensional wigner crystallization caused by magnetic field

It is discussed that two dimensional electrons can crystallize by the application of magnetic field. The critical field, H_c, above which the crystalline state is expected, is evaluated at absolute zero as a function of the carrier density, n, by use of the Lindeman's Law. The theoretical results are discussed in connection to the recent experiment by Kawaji and Wakabayashi.     

Pair breaking parameter of two-dimensional dirty superconductors

Intrinsic mechanism of pair breaking is given for dirty superconducting films. Dynamical interaction between electrons such as Coulomb interaction plays an essential role. The diffusion processes of both density- and pair-fluctuations are also important. The problem of the Thompson's parameter for the Maki term of fluctuation conductivity is solved and the correct dependence of the parameter of the sheet resistance R_sq is given.     

Total synthesis of (+/-)-morphine

[Structure: see text] The morphinan skeleton was effectively synthesized by an intramolecular Mannich-type reaction. Further transformation led to total synthesis of morphine.     

Total synthesis of (-)-kainic acid via intramolecular Michael addition: a second-generation route

A total synthesis of (-)-kainic acid starting from the commercially available 2-azetidinone is described. The key delta-lactone intermediate was concisely prepared from the commercially available azetidinone through the Reformatsky-type reaction and an introduction of a glycine moiety. The construction of the functionalized pyrrolidine ring was executed by a one-pot sequential elimination-Michael addition protocol of a beta-amino-delta-lactone intermediate with high diastereoselectivity.     

A mild inter- and intramolecular amination of aryl halides with a combination of CuI and CsOAc

A unique combination of CuI and CsOAc was found to catalyze aryl amination under mild conditions. The reaction takes place at room temperature or at 90 °C with broad functional group compatibility. The intramolecular reaction was able to form five-, six-, and seven-membered rings with various protecting groups on the nitrogen atom. The scope of the intermolecular amination, as well as its applications to unsymmetrical N,N′-dialkylated phenylenediamines, was investigated.     

Br-radical-mediated [3+2] annulation: synthesis of 2-bromomethyl-substituted alkenylcyclopentanes by the reaction of alkenylcyclopropanes with allyl bromides under photo irradiation

A radical chain addition of allyl bromides 2 to alkenylcyclopropanes 1 resulted in [3+2] annulation to give 2-bromomethylalkenylcyclopentanes 3 in good yields(16 examples). In this reaction, two kinetically fast radical reactions, cyclopropylcarbinyl radical-ring-opening and 5-exo-radical cyclization, preceded the β-fragmentation of a bromine radical to make the formal cycloaddition possible.