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  2. Cis–trans isomerism - Wikipedia

    en.wikipedia.org/wiki/Cis–trans_isomerism

    Another example of this is the relationship between oleic acid and elaidic acid; oleic acid, the cis isomer, has a melting point of 13.4 °C, making it a liquid at room temperature, while the trans isomer, elaidic acid, has the much higher melting point of 43 °C, due to the straighter trans isomer being able to pack more tightly, and is solid ...

  3. Syn and anti addition - Wikipedia

    en.wikipedia.org/wiki/Syn_and_anti_addition

    In organic chemistry, syn-and anti-addition are different ways in which substituent molecules can be added to an alkene (R 2 C=CR 2) or alkyne (RC≡CR). 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.

  4. Descriptor (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Descriptor_(Chemistry)

    See: cis–trans isomerism. cis (left) and trans (right) configured double bond in maleic acid and fumaric acid. cis (left) and trans (right) isomerism in a ring system. The descriptors cis (lat. on this side of) [2] and trans (lat. over, beyond) [3] are used in various contexts for the description of chemical configurations: [4] [5]

  5. Maleate isomerase - Wikipedia

    en.wikipedia.org/wiki/Maleate_isomerase

    In enzymology, a maleate isomerase (EC 5.2.1.1), or maleate cis-tran isomerase, is a member of the Asp/Glu racemase superfamily discovered in bacteria. It is responsible for catalyzing cis-trans isomerization of the C2-C3 double bond in maleate to produce fumarate, [1] which is a critical intermediate in citric acid cycle. [2]

  6. Fumaric acid - Wikipedia

    en.wikipedia.org/wiki/Fumaric_acid

    Fumaric acid or trans-butenedioic acid is an organic compound with the formula HO 2 CCH=CHCO 2 H. A white solid, fumaric acid occurs widely in nature. It has a fruit-like taste and has been used as a food additive. Its E number is E297. [3] The salts and esters are known as fumarates. Fumarate can also refer to the C 4 H 2 O 2− 4 ion (in ...

  7. endo–exo isomerism - Wikipedia

    en.wikipedia.org/wiki/Endo–exo_isomerism

    In organic chemistry, endo–exo isomerism is a special type of stereoisomerism found in organic compounds with a substituent on a bridged ring system. [1] The prefix endo is reserved for the isomer with the substituent located closest, or "syn", to the longest bridge.

  8. Lindlar catalyst - Wikipedia

    en.wikipedia.org/wiki/Lindlar_catalyst

    Alkyne hydrogenation is stereospecific, occurring via syn addition to give the cis-alkene. [4] For example the hydrogenation of acetylenedicarboxylic acid using Lindlar catalyst gives maleic acid rather than fumaric acid. An example of commercial use is the organic synthesis of vitamin A which involves an alkyne reduction with the Lindlar catalyst.

  9. Diels–Alder reaction - Wikipedia

    en.wikipedia.org/wiki/Diels–Alder_reaction

    Stereochemical information of the diene and the dienophile are retained in the product, as a syn addition with respect to each component. For example, substituents in a cis (trans, resp.) relationship on the double bond of the dienophile give rise to substituents that are cis (trans, resp.) on those same carbons with respect to the cyclohexene ...