Exam 2 - Reduction and Hemiacetal Formation Flashcards
___-mediated hemiacetal formation is MORE common than ___-mediated hemiacetal formation.
Acid-mediated is more common than Base-mediated.
A ketone/aldehyde + ___ will create a hydrate.
H2O
In Base-mediated hemiacetal formation, you react a ketone with ___ and ___ in order to make the hemiacetal.
ketone, ethanol, Na(+) (-)OR
Basic conditions: Intermediates must be ___/___ charged.
neutral/negatively charged
A ___ is when OH and OR are on the same C.
hemiacetal
___ conditions: Intermediates must be neutral/positively charged.
Acidic conditions
*Note: Oxygen nucleophiles are ___ nucleophiles.
weaker nucleophiles
You can also add alkynes to ketones/aldehydes by adding ___ with a separate H3O+ acidic workup step afterward. This will create a new ___ group added on the central C, with the O becoming a ___.
Na(+) (-)alkyne-R, alkyne-R, OH
You can also add CN to ketones/aldehydes by adding ___ and ___. This will create a new ___ group added on the central C, with the O becoming a ___.
Na(+) (-)CN, H2O, CN, OH
In Acid-mediated hemiacetal formation, you can also use ___ instead of HCl with the ketone and ethanol.
pTsOH
A ___ is when two OHs are on the same C.
hydrate
Acidic conditions: Intermediates must be ___/___ charged. However, ___ ___ are okay.
neutral/positively charged, however non-basic anions (i.e. Br-, Cl-, etc.) are okay
A hydrate is when two ___ are on the same ___.
two OHs on the same C.
___ conditions: Intermediates must be neutral/negatively charged.
Basic conditions
Ketones are generally ___ stable than aldehydes.
more