Organosulfur Chemistry Flashcards
1
Q
pKa sulfide
A
48
2
Q
pKa sulfoxide
A
35
3
Q
pKa sulfone
A
31
4
Q
reactivity of sulfur compounds
A
sulfone > sulfoxide > sulfide
5
Q
umpolung
A
inverse polarity
6
Q
base needed to deprotonate dithiane
A
nBuLi
7
Q
dithiane
A
acyl anion equivalent
8
Q
how to unmask dithianes
A
oxidant eg m-CPBA then protonation at more basic oxygen, formation of sulfur ylide and finally nucleophilic attack of water
9
Q
Stetter original catalyst
A
NaCN
10
Q
stetter modern catalyst
A
carbene from thiazolium salt
11
Q
stetter reactants and products
A
aldehyde, a,b-unsat carbonyl and catalyst gives 1,4-dicarbonyl
12
Q
base needed to deprotonate sulfonium ylides
A
NaH
13
Q
sulfonium ylide uses
A
epoxidation and cyclopropanation
