Adams Open Formulas

D-Glucose is an aldohexose. Four of the six carbon atoms are chiral carbon atoms. To compare the arrangements of atoms in common, simple monosaccharides, stmctural formulas are written using the convention that all bonds connecting carbon atoms are vertical and project into the plane of the page away from the viewer and the bond to the hydrogen atom and the hydroxyl group on each chiral carbon atom projects out of the plane of the page towards the viewer. Horizontal bonds are often omitted. The acycHc stmctural formula of D-glucose shown is known as the open-chain, or Fischer, formula. If the hydroxyl group on the most distant chiral carbon atom from the top end (the penultimate carbon atom of the stmctures in Figure 1 C-5 of D-glucose) is on the right when the carbon chain of an aldose or ketose is written using this convention, the sugar is said to have the D configuration if that hydroxyl group is on the left, the sugar belongs to the family of L sugars. Most naturally occurring monosaccharides have the D configuration. An exception is arabinose, which most often occurs as L-arabinose [5328-37-0]. AH possible stmctures of the three-, four-, five-, and six-carbon-atom aldoses with the D configuration are given in Figure 1.  [c.473]

The process of engaging the required capabilities must be a formal process so that both the organization in need and the contractor/sub-contractor are protected in the event of a failure to perform, an accident, or a difference of opinion as to terms or performance. Adherence to the provisions of this procedure will help attain good contracting practices and minimize the potential liabilities to the host organization in contractual relationships.  [c.214]

Hydrocarbons, as their name indicates, are componnds of carbon and hydrogen. They represent one of the most significant classes of organic compounds. The scope of hydrocarbons is broad. They include saturated hydrocarbons (alkanes, cycloalkanes) and their derivatives as well as unsaturated alkenes and dienes, acetylenes, and aromatics. In methane (CH4), the simplest satnrated alkane, a single carbon atom is bonded to four hydrogen atoms by sharing electron pairs, i.e., by covalent bonds. In the higher homologues of methane (of the general formula C H2 +2), all atoms are bound to each other by such single [sigma (t), two electron-two center] bonds, with carbon atoms also displaying their ability bind to each other to form C-C bonds. Carbon atoms can be aligned in open chains (acyclic hydrocarbons). Whereas in CH4 the H C ratio is 4, in C2Hg (ethane) it is decreased to 3, in C3H8 (propane) to 2.67, and so on. Alkanes can be straight-chain (each  [c.126]

The carbon signal at 5c = 133.4 splits into a sextet with Jqh Jqh = 6 Hz. This carbon of the benzenoid ring D is therefore attached to part structure A Jqh coupling with one benzenoid proton in meta position, Jqh coupling with methylene protons at Sa = 2.77, Jqh coupling with methylene protons at Sx = 3.49 explains this the resulting doublet of triplets of triplets collapses to a pseudosextet ( sxt ) due to equal coupling constants. Because only one nitrogen atom appears in the empirical formula, substructure A, D and B can be combined to an A-Methylphenylethylamine unit G. Substructures A - F found so far by NMR include five of the seven double bond equivalents. Two remaining double bond equivalents are thus attributed to two additional rings. One ring is closed by the open ortho positions of the phenyl ring in G and the methylenedioxy function C. The other arises from connection of the carboxy carbonyl with the remaining open bonds on the other side of the molecule, completing it to A -methyl-6,7-methylenedioxy-l-oxo-l,2,3,4-tetra-hydroisoquinoline H.  [c.200]

See pages that mention the term Adams Open Formulas : [c.135]    [c.348]    [c.369]   
Standard Handbook of Petroleum and Natural Gas Engineering Volume 1 (1996) -- [ c.86 , c.87 ]