Stereochemistry a vs. b trans- vs. cis-

http://www.elmhurst.edu/~chm/vchembook/209cistrans.html

http://chemwiki.ucdavis.edu/Textbook_Maps/General_Chemistry_Textbook_Maps/Map%3A_Ball_et_al._%22The_Basics_of_GOB_Chemistry%22/13%3A_Unsaturated_and_Aromatic_Hydrocarbons/13.2_Cis-Trans_Isomers_(Geometric_Isomers)

http://chemwiki.ucdavis.edu/Textbook_Maps/General_Chemistry_Textbook_Maps/Map%3A_Ball_et_al._%22The_Basics_of_GOB_Chemistry%22/13%3A_Unsaturated_and_Aromatic_Hydrocarbons/13.2_Cis-Trans_Isomers_(Geometric_Isomers)

http://mcat-review.org/covalent-bond.php

http://openwetware.org/wiki/Image:Simple_Cycloalkanes.png

Enantiomers

(S)-(+)-lactic acid (left) and (R)-(–)-lactic acid (right) are nonsuperposable mirror images of each other

http://en.wikipedia.org/wiki/Enantiomer

http://chemwiki.ucdavis.edu/Organic_Chemistry/Chirality/Diastereomers

Diastereomers –no mirror image, nonsuperimposable

S vs R weight increase

http://en.wikipedia.org/wiki/Absolute_configuration

S vs R

(S)-(+)-lactic acid (left) and (R)-(–)-lactic acid (right) are nonsuperposable mirror images of each other

http://en.wikipedia.org/wiki/Enantiomer

weight increase

From which are they derived?• Alkanes (both normal and branched) –

synthesized by bacteria, algae, and plants

• Common cycloalkane in crude oil• methyl cyclopentane• methyl cyclohexane• ethyl cyclohexane• 1,1,3-trimethyl cyclohexane• decaline (trans-, cis-)

• Diterpanes: C20 –derived from abietic acid (conifer resin)

http://www.scielo.br/scielo.php?pid=S0103-50532003000600017&script=sci_arttext

• Steranes- from sterol• C27 – cholestane• C28 – ergostane, campostane• C29 – Sitostane

http://aapgbull.geoscienceworld.org/content/95/7/1257.figures-only

Petroleum generation in the southeast Texas basin: Implications for hydrocarbon occur-rence at the South Liberty salt dome

Tat Banga, Regina M. Capuano and Kadry K. Bissada, AAPG Bull., 95, 1257-1291

C30-32 steranes may be from bacteria (and higher life forms, but minor)

• Terpenes• Diterpenes – C20• Triterpenes – C30

• hopanoid (C27-C30) -bacteria• extended hopane – bacteria, land

plant• Alkenes – found only rare in petroleum

because the double bond is easily re-duced. Plants and microorganisms pro-duce varieties of olefin

C30

b-Carotene

• Aromatic hydrocarbons –contain at least one benzene ring• benzene, toluene, meta xylene, 1,2,4-

trymethylbenzene are major petro-leum aromatic constituents

• Alkyl benzene

http://en.wikipedia.org/wiki/Xylenetoluene

• Polynuclear aromatics• Naphthalene, anthracene, phenan-

threne

http://en.wikipedia.org/wiki/Xylenetoluene

• Porphirines: “tetraphyrrols” derived from chlorophyll and found in sedi-mentary organic matter and petro-leum

Figure 1. The structures of tetraphenylporphyrin (A) and chlorophyll (B). Ph: Phenyl. Mg: Magnesium. R: Side chain

http://spie.org/x38084.xml

Center atom can be Mg, Fe, V, or Ni.Ni is most stable

• Compounds derived from porphirines:• pyrrol, pyridine

• Compounds derived from lignin

http://commons.wikimedia.org/wiki/

http://www.chem.ucla.edu/harding/IGOC/M/methoxy_group.html

- decomposition of lignin forms phenols

• Lignin

Web Figure 13.4.A Partial structure of a hypothetical lignin molecule from European beech (Fagus sylvatica). The phenylpropanoid units that make up lignin are not linked in a simple, repeating way. The lignin of beech contains units derived from coniferyl alcohol, sinapyl alcohol, and para-coumaryl alcohol in the approximate ratio 100:70:7 and is typical of angiosperm lignin. Gymnosperm lignin contains relatively fewer sinapyl alcohol units. (After Nimz 1974.)

http://5e.plantphys.net/image.php?id=130

• Decomposition of lignin forms phe-nols, a small quantities of phenols have been found in petroleum, but they are more common in sediment and rock extracts

http://chemistry.tutorvista.com/organic-chemistry/phenolic-compounds.html

cresol

Propofol

adrenaline

xylenol

anisol