Answer:
Four possible isomers (1–4) for the natural product essramycin. The structure of compound 1 was attributed to essramycin by 1H NMR, 13C NMR, HMBC, HRMS, and IR experiments.
Explanation:
Three synthetic routes were used to prepare all four compounds (Figure 2A). All three reactions utilize 2-(5-amino-4H-1,2,4-triazol-3-yl)-1-phenylethanone (5) as the precursor, whereas each uses different esters (6–8) to construct the pyrimidinone ring. Isomer 1 was prepared by reaction A, which used triazole 5 and ethyl acetoacetate (6) in acetic acid. This was the reaction used in syntheses of essramycin by the Cooper and Moody laboratories.3,4 Reaction B produced compound 2 (minor product) and compound 3 (major product), which were separated chromatographically. This reaction allowed reagent 5 to react with ethyl 3-ethoxy-2-butenoate (7) in the presence of sodium in methanol, under reflux for 24 h. Compound 4 was prepared by reaction C, which was obtained by reflux of 5 and methyl 2-butynoate (8) in n-butanol.
Density does not change with the amount of matter.
The density of water is 1 g/mL whether you have 1 mL or 1000 mL of water. Density is an i<em>ntensive </em>property.
Mass, volume, and weight change with the quantity of matter. For example, the mass of 1000 mL of water is greater than the mass of 1 mL of water. Mass, volume, and weight are <em>extensiv</em>e properties.
Answer:
Explanation:
We are given two reactions which are the two steps of a mechanism:
......(1)
.......(2)
To determine the net chemical equation, we will multiply equation 2
.......(3)
Adding (1) and (3)
Thus, the net balanced chemical equation is:
B is gas
The chemical element krypton is classed as a noble gas and a nonmetal.
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Answer:
1)Around 450 B.C., the Greek philosopher Democritus introduced the idea of the atom.
2)All matter is made of atoms, Atoms are indivisible and indestructible.Compounds are formed by a combination of two or more different kinds of atoms, A chemical reaction is a rearrangement of atoms.
3)B
Explanation: