Conrotatory and disrotatory — In a conrotatory mode of an electrocyclic reaction (a class of organic chemical reactions) the substituents located at the termini of a conjugated double bond system move in the same (clockwise or counter clockwise) direction during ring opening… … Wikipedia
conrotatory — adjective Describing an electrocyclic reaction in which the substituents at the interacting termini of the conjugated system both rotate in the same sense Syn: antarafacial Ant: disrotatory … Wiktionary
Woodward–Hoffmann rules — The Woodward–Hoffmann rules devised by Robert Burns Woodward and Roald Hoffmann are a set of rules in organic chemistry predicting the stereochemistry of pericyclic reactions based on orbital symmetry. These include electrocyclic reactions,… … Wikipedia
Cheletropic reaction — Pericyclic Reactions Cheletropic reactions are a type of pericyclic reaction. A pericyclic reaction is one that involves a transition state with a cyclic array of atoms and an associated cyclic array of interacting orbitals. A reorganization of σ … Wikipedia
Electrocyclic reaction — In organic chemistry, an electrocyclic reaction is a type of pericyclic rearrangement reaction where the net result is one pi bond being converted into one sigma bond. These reactions are usually unnamed, being categorized by the following… … Wikipedia
Nazarov cyclization reaction — The Nazarov cyclization reaction (often referred to as simply the Nazarov cyclization) is a chemical reaction used in organic chemistry for the synthesis of cyclopentenones. The reaction is typically divided into classical and modern variants,… … Wikipedia
Möbius–Hückel concept — The Möbius Hückel treatment is one of two predicting reaction allowedness versus forbiddeness. The concept is the counterpart of the Woodward Hoffmann approach. The methodology in this treatment utilizes the plus minus sign parity in proceeding… … Wikipedia
Vitamin D — is a group of fat soluble prohormones, the two major forms of which are vitamin D2 (or ergocalciferol) and vitamin D3 (or cholecalciferol).cite web|url=http://dietary supplements.info.nih.gov/factsheets/vitamind.asp|title=Dietary Supplement Fact… … Wikipedia
Diarylethene — In chemistry, diarylethene is the general name of a class of compounds that have aromatic groups bonded to each end of a carbon carbon double bond. The simplest example is stilbene, which has two geometric isomers, E and Z. Under the influence of … Wikipedia
Disrotatory — In a disrotatory mode of an electrocyclic reaction (a class of organic reactions) the substituents located at the termini of a conjugated double bond system move in the opposite (clockwise or counter clockwise) direction during ring opening or… … Wikipedia
