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In stereochemistry, diastereomers (sometimes called diastereoisomers) are a type of stereoisomer. [1] Diastereomers are defined as non-mirror image, non-identical stereoisomers. Hence, they occur when two or more stereoisomers of a compound have different configurations at one or more (but not all) of the equivalent (related) stereocenters and ...
A (4+3) cycloaddition [1] is a cycloaddition between a four-atom π-system and a three-atom π-system to form a seven-membered ring. Allyl or oxyallyl cations (propenylium-2-olate) are commonly used three-atom π-systems, while a diene (such as butadiene) plays the role of the four-atom π-system.
The concepts of syn and anti addition are used to characterize the different reactions of organic chemistry by reflecting the stereochemistry of the products in a reaction. The type of addition that occurs depends on multiple different factors of a reaction, and is defined by the final orientation of the substituents on the parent molecule.
Stereochemistry, a subdiscipline of chemistry, studies the spatial arrangement of atoms that form the structure of molecules and their manipulation. [1] The study of stereochemistry focuses on the relationships between stereoisomers, which are defined as having the same molecular formula and sequence of bonded atoms (constitution) but differing in the geometric positioning of the atoms in space.
This reaction produced the 1,6-addition product 2 in 0% yield, the 1,6-addition product 3 in approximately 99% yield, and the 1,4-addition product 4 in less than 2% yield. This particular catalyst and set of reaction conditions led to the mostly regioselective and enantioselective 1,6-Michael addition of ethyl sorbate 1 to product 3.
If stereochemistry is specified, adjustments must be made; see § Stereochemistry below. The one form of branch which does not require parentheses are ring-closing bonds: the SMILES fragment C1N is equivalent to C(1)N, both denoting a bond between the C and the N. Choosing ring-closing bonds adjacent to branch points can reduce the number of ...
E)-Stilbene, commonly known as trans-stilbene, is an organic compound represented by the condensed structural formula C 6 H 5 CH=CHC 6 H 5. Classified as a diarylethene , it features a central ethylene moiety with one phenyl group substituent on each end of the carbon–carbon double bond .
In chemical nomenclature, a descriptor is a notational prefix placed before the systematic substance name, which describes the configuration or the stereochemistry of the molecule. [1] Some of the listed descriptors should not be used in publications, as they no longer accurately correspond with the recommendations of the IUPAC.