A concise synthesis of pinellic acid using a cross-metathesis approach

A new enantioselective synthesis of pinellic acid, a trihydroxy unsaturated fatty acid exhibiting oral adjuvant activity for nasally administered influenza vaccine, has been accomplished using a cross-metathesis reaction between two terminal olefin intermediates as the key step. This synthesis is the shortest to date, furnishing pinellic acid in 17% overall yield via only seven steps from a readily available known dihydroxy ester.     

Cross patterning on MgO based on dislocations using femtosecond laser irradiation

We show a unique technique to form dense dislocations locally inside a MgO single crystal with a rock-salt type structure using femtosecond (fs) laser irradiation. Cross-shaped patterns of micrometer size, originating from densely introduced dislocations, are formed spontaneously around the focal point. We controlled the three-dimensional propagation of the dislocations by adjusting the pulse energy of the fs laser and NA of objective lens. The technique may open up a new field of dislocation technology for optical applications.     

Noise analysis and design optimization due to pattern processing in perpendicular patterned media

In patterned media, shape characteristics of dots due to processing fluctuation and resolution will become the main source of the noise. The noise due to the roughness of edge line and roundness by the lithographical resolution was analyzed in this paper. Firstly, edge line roughness was re-created by the method in the semiconductor field, and dot physical pattern was generated. We added the physical pattern roundness due to lithographical resolution varied with the ratio of decreased area by over etching. The result indicated those noise sources caused fatal errors. The processing guidance of the dot was formulated.     

Influence of patterning fluctuation on read/write characteristics in discrete track and bit patterned media

The read/write characteristics of non-patterned media (NPM), discrete track media (DTM), and bit patterned media (BPM) are examined by modeling the magnetization distribution of NPM and patterning fluctuation of DTM. By comparing spin-stand measurement with calculation, the magnetization distribution of NPM was well characterized with a new Voronoi cell magnetic cluster model, in which the cluster size at the track edge, 〈D_edge〉, was larger than that at the track center, 〈D_center〉 by a factor of two. Based on an analysis of patterning fluctuations seen in SEM images of DTM, line-edge roughness (LER) was modeled as a long-wavelength center-line roughness (CLR) plus a short-wavelength line-width roughness (LWR). It was confirmed that the standard deviation of the patterning fluctuation was much smaller than that of the magnetic fluctuation for NPM. This allowed DTM to achieve higher off-track performance than NPM. By examining the 747 curves, it was revealed that DTM could have an advantage in track-density of up to approximately 25% assuming patterning fluctuations can be well controlled at high track density. In BPM, fabricating accurate dots is essential. The relationship between dot defect rate and patterning fluctuation was examined, and the maximum allowable standard deviation of LER was derived as 2 nm for achieving 1 Tbspi.     

Synthesis of γ‐Boryl‐Substituted Homoallylic Alcohols with anti Stereochemistry Based on a Double‐Bond Transposition

The stereoselective synthesis of anti isomers of γ‐boryl‐substituted homoallylic alcohols is disclosed. (E)‐1,2‐Di(boryl)alk‐1‐enes undergo Ru‐catalyzed double‐bond transposition with control of the geometry. The in situ generated (E)‐1,2‐di(boryl)alk‐2‐enes add to aldehydes in a stereospecific manner. The alkenylboron group within the product is amenable to a variety of synthetic derivatizations.