Illustrated Glossary of Organic Chemistry Syn addition: An addition reaction in which all new bonds are formed on the same face of the reactant molecule. 1. BH3 2. HOOH, NaOH This hydroboration-oxidation reaction is a syn addition because this reaction delivers an H and OH to the same face of the alkene. + [4+2] This Diels-Alder reaction is a syn c [..]

Illustrated Glossary of Organic Chemistry Syn-periplanar: Two bonds, groups, or other molecular moieties with a 0o dihedral angle (i.e., lying in the same plane and pointing in the same direction). Sawhorse projection    Newman projection In the syn-eclipsed conformation of butane the methyl groups have a syn-periplanar relationship. Verify with a [..]

Illustrated Glossary of Organic Chemistry Transition state (TS, [TS]++): The highest energy structure along the reaction coordinate between reactants and products for every step of a reaction mechanism. SN2 reaction between methyl iodide and hydroxide ion.    An energy profile for the SN2 reaction between methyl iodide and hydroxide ion. The transi [..]

Illustrated Glossary of Organic Chemistry Talose: An aldohexose monosaccharide having the molecular structure shown below. Molecular Structure of (D)-(+)-Talose    Fischer projection

Illustrated Glossary of Organic Chemistry Tautomer: Any molecule in a set of constitutional isomers that are conceptually related by the shift of a hydrogen atom and one or more pi bonds. Tautomers of Acetone Keto form Enol form Tautomers of Acetamide

Illustrated Glossary of Organic Chemistry Tautomerization: The process of isomerization of one tautomer into another tautomer. Mechanism for acid-catalyzed tautomerization of acetone. Mechanism for base-catalyzed tautomerization of acetone.

Illustrated Glossary of Organic Chemistry Tetra-n-butylammonium fluoride (TBAF): A quaternary alkylammonium salt, commonly used to deprotect silyl ethers. Molecular structure of tetra-n-butylammonium fluoride. Application of tetra-n-butylammonium fluoride in silyl ether deprotection: The starting material has two protecting groups (a TMS ether and [..]

Illustrated Glossary of Organic Chemistry tBDMS group (tert-butyldimethylsilyl group): A group consisting of a tert-butyl group and two methyl groups bonded to a silicon atom. Commonly used as a silyl ether protecting group for alcohols. abbreviated as Benzyl tert-butyldimethylsilyl ether. The tBDMS group is shown in red. Related terms: Acetyl grou [..]

Illustrated Glossary of Organic Chemistry tBDPS group (tert-butyldiphenylsilyl group): A group consisting of a tert-butyl group and two phenyl groups bonded to a silicon atom. Commonly used as a silyl ether protecting group for alcohols. abbreviated as Benzyl tert-butyldiphenylsilyl ether. The tBDPS group is shown in red. Related terms: Acetyl grou [..]

Illustrated Glossary of Organic Chemistry Tert-butyl (tert-butyl group; tBu): A portion of a molecular structure which is equivalent to 2-methylpropane minus one hydrogen atom from carbon 2. Sometimes abbreviated as tBu. 2-Methylpropane Tert-butyl group    Related terms: Acetyl group, activating group, acyl group, alkanoyl group, alkoxy group, alky [..]