The role of methionine in protein chain initiation in wheat has been studied. Two chain-initiating methionine tRNAs have been found. One of these is located in the cytoplasm of the wheat cell. This methionyl-tRNA is not formylated by wheat extracts and appears to function in protein chain initiation in the cytoplasm without prior formylation. The other initiating tRNA is from chloroplasts. This...

An efficient total synthesis of (+)-vincristine has been accomplished through a stereoselective coupling of demethylvindoline and the eleven-membered carbomethoxyverbanamine presursor. Demethylvindoline was prepared by oxidation of 17-hydroxy-11-methoxytabersonine, followed by regioselective acetylation with mixed anhydride method. Although an initial attempt of coupling by using demethylvindol...

With 3,3'-bi[benzo[b]thiophenyl] as starting material, dibenzo[d,d']benzo[1,2-b:4,3-b']dithiophene, a [5]heterohelicene, was synthesized efficiently in 60% yield via formylation and McMurry reaction. Cyclopenta[1,2-b:4,3-b']bis(benzo[d]thiophen)-6-one, another interesting helical ketone, was also prepared in 79% yield via deprotonation and ketonization of 3,3'-bi[benzo[b]thiophenyl]. In additio...

Formamide derivatives have been synthesized in excellent yields from amine and formic acid in the presence of a catalytic amount of thiamine hydrochloride (VB1) at 80 !C. The advantages of this method are the use of a cheap, stable, non-toxic, and readily available catalyst, easy work-up, improved yields, and solvent-free conditions. " 2010 Elsevier Ltd. All rights reserved. Formylation of amin...

An efficient, scalable and operationally simple one-pot, 2-step strategy for the nucleophilic formylation of trifluoromethyl ketones is presented. The key step is an unprecedented diaza-carbonyl-ene reaction of formaldehyde tert-butyl hydrazone and trifluoromethyl ketones under solvent-free conditions. This reaction proved to be very fast, clean and high-yielding, affording densely functionalis...

The gene named bciD, which encodes the enzyme involved in C7-formylation in bacteriochlorophyll e biosynthesis, was found and investigated by insertional inactivation in the brown-colored green sulfur bacterium Chlorobaculum limnaeum (previously called Chlorobium phaeobacteroides). The bciD mutant cells were green in color, and accumulated bacteriochlorophyll c homologs bearing the 7-methyl gro...

B(OCH2CF3)3, prepared from readily available B2O3 and 2,2,2-trifluoroethanol, is as an effective reagent for the direct amidation of a variety of carboxylic acids with a broad range of amines. In most cases, the amide products can be purified by a simple filtration procedure using commercially available resins, with no need for aqueous workup or chromatography. The amidation of N-protected amin...