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What does exo and endo mean?
The prefix endo is reserved for the isomer with the substituent located closest, or “syn”, to the longest bridge. The prefix exo is reserved for the isomer with the substituent located farthest, or “anti”, to the longest bridge.
What is endo and exo in organic chemistry?
The ENDO product is the one where the “outside” groups on the diene are on the SAME side of the 6-membered ring as the electron withdrawing group (EWG). The EXO product is the one where the “outside” groups are on the OPPOSITE side of the ring as the 6-membered ring.
Which is more stable endo or exo?
[To jump ahead, here’s a fact we’ll cover in more detail in the next post: most exo products are in fact more stable than the endo products for steric reasons, but the endo product tends to be formed faster. Furthermore, given enough heat, the Diels-Alder product can revert back to starting materials .
What is Endo short for?
Endo, short for ‘endodontic root treatment’ in dentistry, otherwise known as a root canal. Endo, a cycling trick also known as a stoppie, after the possible outcome of flipping “end-over-end” if performed incorrectly. Endo, a slang abbreviation in cycling for an “end over end” accident.
What is endo Rule?
The endo rule for predicting Diels-Alder stereochemistry applies to reactions involving a dienophile with one or more unsaturated substituents. The rule states that the kinetic product is obtained from a transition state in which the dienophile substituent is “endo” with respect to the diene.
Why is Endo preferred over Exo?
The endo product is kinetically favored, which means that under conditions of low temperature and limited time, it will be the major product that is formed. This is because the transition state of the formation of the endo product is lower in energy due to overlap of secondary orbitals.
How can you tell the difference between exo and endo products?
Note that the endo product has the methyl groups on the same face of the ring as the aldehyde (both dashes, as pictured, or both wedges, as in the enantiomer). The exo product has the methyl groups on the opposite face of the ring as the aldehyde.
What is Endo in medicine?
Endometriosis, frequently referred to as just “endo”, is a genetic disease that affects women and causes pain, inflammation, and infertility. What this means is that one person may have mild disease and severe pain, whereas someone else could have severe disease and minimal symptoms.
What does exo stand for?
EXO. EXO stands for “EXOPLANET,” meaning a planet that is out of our solar system. Who could beat that? They want their stardom to reach beyond our solar system and their music to feel ‘out of this world’. They were voted as the group with the best name branding, along with TWICE.
What does an endo and an exo product look like?
The two molecules approach with minimal overal between their faces; they combine edge-on. The exo product that results has a sort of Z-shape. An endo addition looks more like this, schematically. Two cyclic molecules approach each other so that there is maximum overlap between their faces.
Where does the term Endo come from in biology?
It is derived from the Greek exo meaning “out of” or external. Similarly, what is a Endo? So back to endo- the formal definition is “endometrial glands and stroma existing outside the endometrial cavity”. Essentially, it is tissue that resembles the endometrium (lining of the uterus), that exists other places.
Where do you find the prefix exo in chemistry?
The prefix exo is reserved for the isomer with the substituent located farthest, or ” anti “, to the longest bridge. Here “longest” and “shortest” refer to the number of atoms that comprise the bridge. This type of molecular geometry is found in norbornane systems such as dicyclopentadiene. The terms endo and exo are used in a similar sense in…
What does an endo addition look like in chemistry?
An endo addition looks more like this, schematically. Two cyclic molecules approach each other so that there is maximum overlap between their faces. The endo product that results has a kind of C-shape. Let’s look at these two modes of addition with real molecules. Here we are adding furan, the diene, to maleic anhydride, the dienophile.