Abstract: A process for the preparation of an .alpha.,.beta.-unsaturated C.sub.3 -C.sub.6 carboxylic acid of greater than 98% purity, which combines fractional distillation and melt crystallization procedures.

Abstract: Described is a new immunosuppressant, L-683,756, a bisdemethylated, ring rearranged derivative of L-683,590, produced under fermentation conditions utilizing the microorganism, Actinoplanacete sp. (Merck Culture Collection MA 6559) ATCC No. 53771. The macrolide immunosuppressant is useful in preventing human host rejection of foreign organ transplants, e.g. bone marrow and heart transplants.

Abstract: Linear 1-olefins are prepared from internal olefins by (i) reacting them in the presence of an isomerization catalyst and a tri-lower alkyl aluminum so as to cause internal olefin to isomerize to 1-olefins which displace the lower alkyl groups to form a trialkyl aluminum compound in which at least one of the alkyl groups is a linear alkyl derived from the 1-olefin, and, thereafter, (ii) reacting the trialkyl aluminum compound with a 1-olefin so as to displace the linear alkyl from the trialkyl aluminum compound, thereby forming a linear 1-olefin product which is substantially free of internal olefins.

Abstract: Vicinally diacyloxy-substituted compounds of the formulae Ia, Ib, Ic and IdR.sup.1 [vic. (O--CO--R.sup.2).sub.2 ]--H (Ia)R.sup.3 [vic. (O--CO--R.sup.2).sub.2 ]--CO--OR.sup.4 (Ib)R.sup.3 [vic. (O--CO--R.sup.2).sub.2 ]--CO--OR.sup.5 [vic. (O--CO--R.sup.2).sub.2 ] (Ic)R.sup.6 --CO--OR.sup.5 [vic. (O--CO--R.sup.2).sub.2 ] (Id)in whichR.sup.1 is a trivalent saturated C.sub.6-22 hydrocarbon radical,R.sup.2 is a C.sub.1-3 alkyl radical,R.sup.3 is a trivalent saturated C.sub.10-21 hydrocarbon radical,R.sup.4 is a C.sub.1-22 alkyl radical,R.sup.5 is a trivalent saturated C.sub.16-22 hydrocarbon radical, andR.sup.6 is a C.sub.1-21 alkyl radical,are prepared from the corresponding epoxidized compounds by reaction with C.sub.2-4 carboxylic anhydrides at elevated temperature in the presence of catalytic quantities of carboxylic acids corresponding to the anhydrides and/or catalytic quantities of sulfuric acid.

Abstract: The use of TiO.sub.2 spin-on glass films for reduction of electrostatic charging of a semiconductor substrate upon electron beam exposure is described. Specifically, the disclosure relates to electron beam lithographic processing during semiconductor device or mask fabrication. The TiO.sub.2 glass films may also be utilized for charge dissipation during ion implantation. A thin TiO.sub.2 composition spin-on glass film is used as a charge dissipation layer. This mechanism is effective as a resolution enhancement mechanism during electron beam or ion beam processing of semiconductors. The TiO.sub.2 composition films are prepared from spin-on materials that consist of partially hydrolyzed organotitanium species dissolved in organic solvents which produce glassy films of TiO.sub.2 upon application to silicon and other substrates and subsequent heating. The films are completely amorphous, have extremely low pinhole and particulate densities, are uniform in thickness and free of radial striations.