Organic Chemistry II Exam 2

In ketones and aldehydes, the C=O carbonyl has a partial __________ charge on the C and a partial _________ charge on the O

positive; negative

Based on respective partial charges, nucleophiles are drawn to the _ atom and electrophiles are drawn to the _ atom in a C=O bond.

C; O

When naming aldehydes and ketones, start with the end ________ (closest or furthest) from the carbonyl

closest

Aldehydes end with -__ and ketones end with -____

al; one

Synthesis of aldehydes/ketones: HO-CH₂-R → R-C=O. What goes on the reaction arrow?

PCC

Synthesis of aldehydes/ketones: H-C-(triple bond)C-R →

R-C(O)-R. What goes on the reaction arrow? (1. and 2.)

1)R₂BH

2)H₂O₂, OH⁻

R-C(OH)-R' --> R-C(O)-R'. What goes on the reaction arrow?

Na₂Cr₂O₇

R-CC-R --> R-C(O)-R. What goes on the reaction arrow? (1. and 2.)

H₂SO₄; HgSO₄

Nucleophilic Addition: ___________- turns an aldehyde or ketone into a geminal diol

hydration

Nucleophilic hydration has to be catalyzed by an ____ or ____

acid; base

Nucleophilic addition: ______________- ____ catalyzed addition of -CN

cyanohydrin; base

In cyanohydrin formation, -CN is usually introduced as ____ or ___ with ___, then acid

NaCN; KCN with H₂O

A cyanohydrin treated with H₃O⁺ with form a __________ ____ in the place of the ⁻CN

carboxylic acid

A cyanohydrin treated with 1)__ over 2)__ or 1)______ over 2)____ will result in a protenated C-N triple bond

Ni; H₂; LiAlH₄; H₂O

Speed of cyanohydrin formation is based on the strength of the ______ _________ charge on the carbonyl carbon, which is affected by surrounding groups

partial positive

Nucleophilic additions: ______- splits carbonyl bond to form -OH or OR bonds

acetals

Where 2 equiv. -OR creates an ______, 1 equiv. -OR only creates a __________

acetal; hemiacetal

Acetal reactions can be reversed using 1)______ over 2) ___ (making them useful in protecting C=O bonds)

LiAlH₄; H₃O⁺

Nucleophilic additions: ________- the addition of a primary amine (NH₂R)

imines

Imine reactions joins two molecules with the elimination of ___ and requires trace ____

H₂O; acid

Imine reactions result in the _ atom double bonded to the carbon previously double bonded to O

N

Nucleophilic additions: ___________- addition of a secondary amine (R₂NH)

enamines

Unlike imine reactions, enamines form a C=_ bond, but like imines, they require presence of a trace acid

C

Wittig reactions uses a phosphorous _____ to eliminate a C=O bond and create an ______

ylide; alkene

-oic acid

-oyl acid

-anhydride

-ate or -oate

-amide