DIAZOALDEHYDE CHEMISTRY .1. TRANSDIAZOTIZATION OF ACYLACETALDEHYDES IN NEUTRAL-TO-ACIDIC MEDIUM - A DIRECT APPROACH TO THE SYNTHESIS OF ALPHA-DIAZO-BETA-OXOALDEHYDES)


SEZER O. , ANAC O.

HELVETICA CHIMICA ACTA, cilt.77, ss.2323-2334, 1994 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 77 Konu: 8
  • Basım Tarihi: 1994
  • Doi Numarası: 10.1002/hlca.19940770819
  • Dergi Adı: HELVETICA CHIMICA ACTA
  • Sayfa Sayıları: ss.2323-2334

Özet

First ever non-deformylating transdiazotization of acylacetaldehydes was achieved: the reactions of 2-azido-1-ethylpyridinium tetrafluoroborate (4) with acylacetaldehydes 3 proceeded partially without deformylation to yield 16 new alpha-diazo-beta-oxoaldehydes 1 along with diazomethyl ketones 2, especially in the presence of NaOAc (Scheme 1, Tables 1 and 2). The product distribution was substituent-dependent and could be correlated quantitatively. This new diazotization reaction appears as an alternative, direct, and more general method for the synthesis of these diazooxoaldehydes. alpha-Oxocycloalkanecarbaldehydes 5 gave only traces (if any) of alpha-diazocycloalkanones 7, and rearrangement products 6 were isolated (Scheme 2). Mechanisms of the reactions are discussed (Schemes 4 and 5).