The best replacement for aldehyde is ketone.

The best alternatives to aldehyde are rated as following:
★★★★★  ketone
★★  ketone ir
★★  ketone more acidic
★★  carboxylic acid
★★  ketone more reactive
★  alcohol higher boiling point
★  ketone higher boiling point
★  ketone boiling point
★  ketone ir spectrum
★  formaldehyde
★  alcohol boiling point
★  ketone better electrophile
★  ketone ir spectroscopy
★  ester
★  ketone electrophile
  carbonyl
  aldose
  ketone reactivity
  acetaldehyde
  formaldehydes

Your alternative for aldehyde is not listed? Suggest!
Speaking about aldehyde, one probably shouldn't forget about amine.

Other search terms related to aldehyde and their ratings are:
★★★★★ amine
★★★ benzene ring
★★★ nabh4
★★★ grignard reagent
★★ hcn
★ toluene
★ h2cro4
★ socl2
kmno4
tollens reagent
sodium bisulfite
carboxylic acid
schiff's reagent
phenol
pcc
c5h8o
You have in mind a companion for aldehyde and it is not yet here? Propose!



Google Trends

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aldehyde
ketone
ketone ir