Asymmetric 1,4-Additions to Y-Menthyloxybutenolides;(part IV1) two Enantioselective Syntheses of 2-Methyl-1,4-Butanediol

DCT-like Transform for Image Compression Requires 14 Additions Only

A low-complexity 8-point orthogonal approximate DCT is introduced. The proposed transform requires no multiplications or bit-shift operations. The derived fast algorithm requires only 14 additions, less than any existing DCT approximation. Moreover, in several image compression scenarios, the proposed transform could outperform the well-known signed DCT, as well as state-of-the-art algorithms.

Curing of Epoxy Resins with 1 - [ Di ( 2 - Chloroethoxyphosphinyl ) methyl ] - 2 , 14 - and - 2 , 6 - Diamiilobenzene

BA 14-2-bradley

This paper details the comparison of a built coupled volume concert hall and a computergenerated model of the hall. Coupled volume spaces typically have an auxiliary volume connected to the main volume through an acoustically transparent aperture. In this type of space, architectural parameters such as volume size and surface absorption can be designed to produce a non-linear reverberant decay,...

Enantioselective thiourea-catalyzed additions to oxocarbenium ions.

Asymmetric, catalytic reactions of oxocarbenium ions are reported. Simple, chiral urea and thiourea derivatives are shown to catalyze the enantioselective substitution of silyl ketene acetals onto 1-chloroisochromans. A mechanism involving anion binding by the chiral catalyst to generate a reactive oxocarbenium ion is invoked. Catalysts bearing tertiary benzylic amide groups afforded highest en...

Cover Vol.14, No.2 April 2017