Study Set Content:
- These are disubstituted alkenes
Cis-Trans Isomers of Alkenes
two substituents other than hydrogen are bonded to the double-bond carbons.
Disubstituted
Only when both carbons are bonded to two different groups are
cis-trans isomers possible.
- use for trisubstituted and tetrasubstituted alkenes
Sequence Rules: The E,Z Designation
the higher rank groups are on opposite side
E geometry - "entgegen : opposite"
the higher rank groups are on the same side (ZAME ZIDE)
Z geometry - "zusammen : together"
(Higher-ranked groups are on opposite sides.)
E double bond
(Higher-ranked groups are on the same side.)
Z double bond
Rule 1,2 and 3
Considering the double-bond carbons separately, look at the atoms directly attached to each carbon and rank them according to atomic number.
RULE 2
If a decision can't be reached by ranking the first atoms in the substituents, look at the second, third, or fourth atoms away from the double-bond carbons until the first difference is found.
RULE 3
Multiple-bonded atoms are equivalent to their
same number of single-bonded atoms.
Substituent groups containing double bonds are:
H2C=CH- Vinyl group
H2C=CH-CH2- Allyl group
- he simplest alkyne, is used in torches to generate temperatures of around 3,000 degrees Celsius to weld metal by generating oxy-acetylene welding.
Acetylene
- It is also used as a starting material in the synthesis processes used to make polymers, and as a solvent.
alkyne
Alkynes are generally used as the starting materials for the manufacture of a large number of organic compounds of industrial importance such as,
- chloroprene, vinyl chloride etc.
- Alkynes are also highly important parts of some (blank) agents.
antitumor
was used to describe such fragrant substances as benzaldehyde (from cherries, peaches, and almonds), toluene (from Tolu balsam), and benzene (from coal distillate).
aromatic
the class of compounds that contain six-membered benzene-like rings with three double bonds.
aromatic
Some aromatic compounds found in
coal tar
Pharmaceutical Preparations
of aromatic compounds
- Steroids (e.g., estrone)
- Lipitor
- Benzene causes leukopenia on prolonged exposure and should not be used as laboratory solvent.
- Major source: Coal and Petroleum
Benzene (C6H6) has eight fewer hydrogens than
- alkane (C6H14) and is clearly unsaturated
- A six-membered ring with alternating double and single bond.
benzene
