6 - HETEROCYCLES Flashcards
what is a heterocyclic compound?
molecules in which one or more rings contain at least one other atom than carbon
common atoms are O, N, S, P etc
what is the structure of pyridine?
what is the structure of pyrrole?
what is the structure of furan?
what is the structure of thiopene?
what is Huckel’s rule for aromaticity?
of pi electrons in ring=4n+2
why can the lone pairs of pyridine not be delocalised into the aromatic ring?
that is because the sp2 orbital is perpendicular to the orbitals of the ring
it can react with H+ though
why can pyrrole not react with weak acids?
the lone pair is part of the aromatic system, it’s going to be really hard to give it up
what is the difference between the pKa and the pKaH?
the pKaH is the pKa of the conjugate acid
what is an enamine vs an imine?
imine: C=N double bond
enamine: C=C double bond next to an N
primary vs secondary amines and the resulting product when reacting with a ketone?
a primary amine will react with a ketone to form an imine (resonance structure with enamine)
a secondary amine will react with ketone to give an enamine
why are imines favored over enamines?
C=N bond is stronger than C=C
mechanism of acid hydrolysis to make a ketone?
when might N alkylation occur?
when the alkyl halide is small
stork enamine synthesis method
