McMurry (Kap 13.1-13.2) - Naming and properties of alcohols, phenols and thiols Flashcards
Alcohols are named as primary, secondary and tertiary depending on the numbers of organic groups (R) bonded to the hydroxyl bearing carbon.
How is it?
Primary alcohol = one R group and 2 H bonded to the carbon bonded to the OH group.
Secondary alcohol = two R group and 1 H bonded to the carbon bonded to the OH group.
Tertiary alcohol = three R group bonded to the carbon bonded to the OH group.
Naming of alcohols, phenols and thiols can be seen on page 437-439
Common names for alcohols on page 438
Naming of alcohols, phenols and thiols can be seen on page 437-439
Common names for alcohols on page 438
What are some of the properties of alcohols, phenols, and thiols?
You can see the table of acidity constant for some alcohols, phenols and thiols on page 440.
Alcohols and phenols have nearly the same geometry around the oxygen atom as water (C-O-H bond angle is cirka tetrahedral value 109 - and the O atom is sp3 hybridized).
Alcohols and phenols have higher boiling points (like water) - because of hydrogen bonding.
Alcohols and phenols are both weakly acidic and basic (like water) (alkoholer med stærke syrer agerer som baser, men alkoholer med vand reagerer som syre).
Phenoler and thiols are more acidic then water.
You can see the table of acidity constant for some alcohols, phenols and thiols on page 440.
Because alcohols are weak acids, do they react with weak bases?
No they dont (such as amines or bicarbonate ion).
React with strong bases such as NaOH, NaH, NaNH2, and grignard reagents.
Alcohols are themselves basic reagents used in organic chemistry, named Alkoxides - how are they named?
By adding the suffix -ate to the name of the alcohol.
Methanol = Methanolate.
Are phenols and thiols more or less acidic then alcohols?
Almost million times more acidic.
Why are phenols and thiols more acidic?
Phenols are more acidic due to the resonance stabilization of the phenoxide ion.
Delocalization of the negative charge on the O atom stabilizes the molecule making it less attracted to the H+ (weaker base), but also a stronger acid (because it deprotonates easier).
Substituted phenols can either be more acidic or less acidic depending on whether the substituent is e-withdrawing or e-donating.
Explain how?
Phenols with electron withdrawing substituent = more acidic (delocalize the negative charge) (more stable conj.base = stronger conj. acid).
Phenols with electron donating substituent = less acidic (they concentrate the negative charge).
