CON group

In the reactions of azulene with trimethylsilylruthenium carbonyl complexes in refluxing heptane, there occurs a migration of organosili-con groups from metal to ligand to give complexes of silylated azulenes (94) ... 

AMIDE An organic compound that includes the CON group bound to hydrogen. 

Figure 5.13 Endotoxin-induced leukopenia in rats pretreated with LY171883 (LY), 30 mg kg or isovolumetric vehicle (CON), 10 min before administration of S. enteritidis endotoxin (40mgkg ). LY or vehicle was started as an infusion I0mgkg h at 30min postendotoxin. The Con group exhibited a significantly more severe leukopenia (0—180) compared with the LY group (analysis of variance, p < 0.001). WBC, white blood cells. From Cook et reprinted with permission of American Society for Pharmacology and...

Values represent mean SD (n = 22-24 n = 12 for pentabarbitone group) pentabarbitone differed from CON group, P< 0.05. 

Example Hthanc is stable in the staggered gauche) con formation. The transition state for rotating a methyl group in ethane has the eclipsed con form at ion, A gcom etry optim i/ation start in g from an eclipsed eon formation yields th e tran sition state. 

If alOTU 1 or alom j is a hydrogen, Ih e d eforin anon (r-r,j) is considered lo be zero. Thus, no slrelch-bend inleraciion is defined for XHp groups. The slrelch-bend force con slams are incorporated into lb e program and you canriol modify Ihcm. If R is an alom otb er b y dm gen, tb e values of lhe stretcb -bend force eon si an Is are ... 

Periodic boundary conditions can also be used to simulate solid state con dition s although TlyperChem has few specific tools to assist in setting up specific crystal symmetry space groups. The group operation s In vert, Reflect, and Rotate can, however, be used to set up a unit cell manually, provided it is rectangular. 

An sp -fip2 or sp -sp - single bond where the sp atom is in Group VIA (for exam pie. the C-0 bond of vinyl alcoholjhasa two fold barrier with an optimal plan ar con figuration described bv V2=+2.0 kcal/inol. 

Terminal alkyne anions are popular reagents for the acyl anion synthons (RCHjCO"). If this nucleophile is added to aldehydes or ketones, the triple bond remains. This can be con verted to an alkynemercury(II) complex with mercuric salts and is hydrated with water or acids to form ketones (M.M.T. Khan, 1974). The more substituted carbon atom of the al-kynes is converted preferentially into a carbonyl group. Highly substituted a-hydroxyketones are available by this method (J.A. Katzenellenbogen, 1973). Acetylene itself can react with two molecules of an aldehyde or a ketone (V. jager, 1977). Hydration then leads to 1,4-dihydroxy-2-butanones. The 1,4-diols tend to condense to tetrahydrofuran derivatives in the presence of acids. 

As just noted (Section 2 7) CH3 is called a methyl group In addition to having methyl groups at both ends n butane contains two CH2 or methylene groups Isobutane con tains three methyl groups bonded to a CH unit The CH unit is called a methme group... 

It IS convenient m equations such as this to represent generic alcohols and alkyl halides as ROH and RX respectively where R stands for an alkyl group In addition to con venience this notation lets us focus more clearly on the functional group transformation that occurs the OH functional group of an alcohol is replaced as a substituent on car bon by a halogen usually chlorine (X = Cl) or bromine (X = Br)... 

Many compounds contain more than one functional group Prostaglandin Ei a hormone that regulates the relaxation of smooth muscles con tains two different kinds of carbonyl groups Classify each one (aldehyde ketone carboxylic acid ester amide acyl chloride or acid anhydride) Identify the most acidic proton in prostaglandin Ei and use Table 1 7 to estimate its pK ... 

Construct a molecular model corresponding to the Fischer projection of rneso 2 3 dibro mobutane Convert this molecular model to a staggered conformation in which the bromines are anti to one another Are the methyl groups anti or gauche to one another in this staggered con formation" ... 

Electrophilic addition (Section 11 16) An aryl group stabilizes a benzylic carbocation and con trols the regioselectivity of addition to a double bond involving the benzylic carbon Markovni kov s rule is obeyed... 

An important difference between Fnedel-Crafts alkylations and acylations is that acyl cations do not rearrange The acyl group of the acyl chloride or acid anhydride is transferred to the benzene ring unchanged The reason for this is that an acyl cation is so strongly stabilized by resonance that it is more stable than any ion that could con ceivably arise from it by a hydride or alkyl group shift... 

Turning now to electrophilic aromatic substitution in (trifluoromethyl)benzene we con sider the electronic properties of a trifluoromethyl group Because of their high elec tronegativity the three fluorine atoms polarize the electron distribution m their ct bonds to carbon so that carbon bears a partial positive charge... 

Much of the chemistry of diols—compounds that bear two hydroxyl groups—is analo gous to that of alcohols Diols may be prepared for example from compounds that con tain two carbonyl groups using the same reducing agents employed m the preparation of alcohols The following example shows the conversion of a dialdehyde to a diol by... 

With ketones the e ending of an alkane is replaced by one in the longest con tinuous chain containing the carbonyl group The chain is numbered in the direction that provides the lower number for this group The carbonyl carbon of a cyclic ketone is C 1 and the number does not appear m the name... 

Two methods for converting carbonyl groups to methylene units are the Clem mensen reduction (zinc amalgam and con centrated hydrochloric acid) and the Wolff-Kishner reduction (heat with hydra zine and potassium hydroxide in a high boiling alcohol)... 

Table 17 3 compares the equilibrium constants for hydration of some simple aldehydes and ketones The position of equilibrium depends on what groups are attached to C=0 and how they affect its steric and electronic environment Both effects con tribute but the electronic effect controls A hydr more than the steric effect... 

Many of the most interesting and useful reactions of aldehydes and ketones involve trans formation of the initial product of nucleophilic addition to some other substance under the reaction conditions An example is the reaction of aldehydes with alcohols under con ditions of acid catalysis The expected product of nucleophilic addition of the alcohol to the carbonyl group is called a hemiacetal The product actually isolated however cor responds to reaction of one mole of the aldehyde with two moles of alcohol to give gem mal diethers known as acetals... 

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