7b Flashcards

1
Q

morita baylis hillman recognition

A

u have an oh, double bond and a carbonyl

on consecutive carbons

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2
Q

how does a morisa baylis hillam reaction occur

A

u have a nuc (either DABCO or a phsophine nuc - pph3)

this undergoes a conjugate addition reaction and forms an enolate

the enolate attacks an aldehyde // another carbonyl

this carbonyl is protonated to form oh

a beta hydrogen is then removed with a base to form another enolate

this enolate is used to kick off the pph3 // DAPCO original nuc

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3
Q

when we do conjugate addition,, what should we look out for

A

we need to make sure that the double bond we attack isnt part of an aromatic system

we need to make sure we arent breaking aromaticity.

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4
Q

robinson annulation,, how can we tell this is gonnna occur

A

one molecule with enolisable protons (aka protons between // near a carbonyl)

one molecule with alkene carbonyl conjugation (where conjugate addition can occur)

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5
Q

steps of a robinson annulation reaction

A
  • base deprotonates a molecule and forms an enolate
  • enolate is used as the base for conjugate addition
  • enolate formed by conjugate addition attacks H from solvent to saturate the double bond to form an alkane.
  • base deprotonates a H to form an enolate (this enolate is gonna be used to attack a carbonyl C so look at ur options)
  • enolate attacks carbonyl C
  • o- is protonated to give OH
  • enolate is formed using base and deprotonation of a H
  • OH is eliminated
  • alkene and carbonyl are in conjugation.
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