Ch. 13-16 info Flashcards
a lack of free bond rotation, for example, in small rings or with alkenes, can make hydrogens bonded to the same carbon atom
nonequivalent
nearby electronegative atoms have a … effect in NMR
deshielding
in general, the higher the percent of s-character in a hybrid orbital, the … the deshielding effect on itself and adjacent atoms
greater
the induced local magnetic fields in pi bonds either add to or subtract from the applied field depending on the … of the induced electron density circulation relative to the atom in question
geometry
C13-NMR tells you how many … C atoms are in a molecule and … of C atoms are present but it DOES NOT tell you how many C and H there are total
nonequivalent; what kinds
Grignard reagents are prepared by reacting alkyl, aryl, or alkenyl halides with a slight excess of .. in an … solvent
magnesium metal; ether
organolithium reagents are prepared by reaction of an alkyl, aryl, or alkenyl halide with … equivalents of …
two; lithium metal
treatment of a Grignard reagent with an epoxide followed by protonation of the magnesium alkoxide salt in aqueous acid gives an … with its carbon chain extended by … atoms
alcohol; two carbon
two equivalents of organolithium compounds react with one equivalent of a … salt, usually …, to give useful reagents called Gilman reagents
Cu(I); CuI
gilman reagents react with … and … to form new carbon-carbon bonds
haloalkanes; haloalkenes
gilman reagents also react with oxiranes to give … products with C-C bond formation following an acid aqueous workup
alcohol
carbenes are prepared from … or … of diazo species such as diazomethane
photolysis; thermolysis
dichlorocarbene is prepared from the reaction of … with a …
chloroform; strong base
a useful carbenoid is the simmons-smith reagent prepared from … (…) and …
diiodomethane (CH2I2); Zn(Cu)
dichlorocarbene and the simmons-smith reagent react stereospecifically with alkenes to give ..
cyclopropanes (dichlorocarbene has 2 Cl instead of 2 H though)
treating an aldehyde or ketone with a triphenylphosphonium ylide (.. reagent) gives an …
wittig; alkene
wittig reagent formed by treatment of PPh3 with a … or … followed by treatment with a base such as …
haloalkane; haloalkene; BuLi
water is removed from reactions to favor acetal formation using a
dean-stark trap
Imine functional group:
R2C=NR
enamine functional group:
R2C=CR-NR2
hydrazine:
H2NNH2
addition of ammonia or a primary amine to an aldehyde/ketone forms an ..
imine
addition of a secondary amine to an aldehyde/ketone forms an
enamine
addition of hydrazine to aldehyde/ketone gives a
hydrazine
In reductive amination, ketones or aldehydes react with … in the presence of an appropriate reducing agent such as … to give substituted amines
amines; NaBH3CN
aldehyde and ketone carbonyl groups can be reduced to methyl/methylene groups, using two reactions:
the clemmensen reduction uses … in strong acid (HCl) and is used when molecule is stable to strong acid
wolff-kishner reaction uses … and … (KOH)and is used when the molecule is stable to strong base
Zn(Hg); hydrazine (N2H4); base
