TERM 1
Preparation of Alcohols (I) 1-5
DEFINITION 1
Hydration of alkenes: R2C=CHR' + H2O --H (+)--> R2COH-CH2R' Hydroboratio n-
oxidation of alkenes: R2C=CHR' --1.B2H6/2 . H2O2,HO--> R2HC-CHOHR'
Hydrolysis of alkyl halides: RX + HO --> ROH + X Grignard reagents or
organolithium reagents react with carbonyl co mpounds Reduction of aldehydes
and ketones Reduction of aldehydes gives 10 alcohols . Reduction of ketones
gives 20 alcohols Reduction could use cataly tic hydrogenation reaction.
Reduction could use metal hydride reducing agents Hydride (H-) attacks the C=O
carbon to form a tetrahedral intermediate; prot onation of negatively charged O
on the tetrahedral intermediate will give alcoh ol as the final product. Metal
hydride reduction is selective, only C=O is r educed, C=C wont be reduced.
TERM 2
Preparation of Alcohols (II) 1-4
DEFINITION 2
Reduction of carboxylic acids or esters produc es 10 alcohols LiAlH4 is the only
reactive reducing agent for reduction of carbox ylic acids Preparation of alcohols
from epoxides Reaction of Grignard reagents or organol ithium with epoxides
gives alcohols The resultant alcohols contain more carbons than the alkyl halide
from which the RMgX or RLi is prepared. If th e epoxide is unsymmetrically
substituted, the carboanion (R-) from the orga nometallic compounds will attack
the less substituted carbon on the epoxides. Preparation of diols Diols are
molecules containing two OH groups Diols are prepared by reactions used to
prepare alcohols Reduction of dialdehydes , d iketones, dicarboxylic acids, or
diesters Could use catalytic hydroge ns of dialdehydes or diketones Or use NaBH4
or LiAlH4 as the reducing reagent Hydroxylatio n of alkenes gives vicinal diols
OsO4 is the key reagent, it forms a cyclic os mate ester with alkenes. Reaction is
stereospecific syn-addition.
TERM 3
Reactions of Alcohols 1-4
DEFINITION 3
Conversion of alcohols to ethers Acid-catalyze d condensation reaction Reaction is
reversible Follows SN2 mechanism, 10 alco hols are most favorable Esterification
Reaction of an alcohol with a carboxylic acid, or an acyl chloride, or an acid
anhydride will yield an ester. The reaction with an acid requires acid catalyst,
while reaction with acyl chloride and acid anh ydride requires weak base
(pyridine). Oxidation of alcohols 10 alcohols can be oxidiz ed to aldehydes (by
PDC, PCC or chlorodimethylsulfonium ion) , or to carboxylic acids (by K2Cr2O7 +
H2SO4 + H2O) 20 alcohols can be oxidized to ketons by using either PDC, PCC,
chlorodimethylsulfonium ion, or K2Cr2O7 + H2SO4 + H2O The resultant carbonyl
compounds have the same number of carbo ns to those of the starting alcohols.
Oxidative cleavage of vicinal diols Vicinal diols can reac t with HIO4 (periodic acid)
to yield two carbonyl compounds (aldehyde o r ketone)
TERM 4
Nomenclature of thiols
DEFINITION 4
Nomenclature of thiols Analogous to alcohols, but suffix is -
thiol rather than ol. Final -e of alkane name is retained, not
dropped as with alcohols. Numbering the chain in the
direction that gives the lower locant to the carbon bearing
the SH group. When the SH group is referred as a
substituent, it is called mercapto or sulfanyl group.
TERM 5
Naming ethers, epoxides and sulfides
DEFINITION 5
Naming ethers, epoxides and sulfides Ethers and epoxides contain
C-O-C bond, while sulfides contain C-S -C bond. Substitutive IUP AC
names of ethers and sulfides Name a s alkoxy derivatives of
alkanes for ethers. Name as alkylthio derivatives of alkanes for
sulfides. Functional class IUPAC name s of ethers and sulfides
Name the groups attached to oxyge n in alphabetical order as
separate words; "ether" or sulfide is th e last word.
