Total synthesis of spicamycin

J Org Chem. 2002 May 3;67(9):2874-80. doi: 10.1021/jo010925c.

Abstract

The first total synthesis of one of the spicamycin congeners, SPM VIII (3), is described. A preliminary model study for construction of the characteristic N-glycoside linkage in spicamycin using tetra-O-benzyl-beta-D-mannopyranosylamine (13) and halopurines 5 revealed that Pd-catalyzed conditions successfully provided the coupling products 14 and 15 in good yields. It was also shown that thermal anomerization of the N-glycosides easily occurred, which resulted in the predominant formation of the beta-anomer as the thermodynamically favored compound, and the activation energy of anomerization of 15 was estimated to be ca. 30 kcal/mol. The novel aminoheptose unit of spicamycin 6 was prepared stereoselectively by carbon elongation of an acyclic aldehyde, prepared by ring cleavage reaction of a highly functionalized cyclohexane derived from naturally abundant myo-inositol. The Pd-catalyzed coupling reaction of the beta-heptopyranosylamine 6 with protected 6-chloropurine 5d, followed by deprotection, provided spicamycin amino nucleoside 2, whose condensation with dodecanoylglycine completed the total synthesis of 3. This study confirmed the proposed unique structure of a novel nucleoside antibiotic.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / chemical synthesis*
  • Anti-Bacterial Agents / chemistry*
  • Catalysis
  • Glycosides / chemistry
  • Glycosylation
  • Inositol / chemistry
  • Kinetics
  • Models, Molecular
  • Molecular Structure
  • Palladium / chemistry
  • Purine Nucleosides / chemical synthesis*
  • Purine Nucleosides / chemistry*
  • Stereoisomerism
  • Structure-Activity Relationship

Substances

  • Anti-Bacterial Agents
  • Glycosides
  • Purine Nucleosides
  • SPM VIII
  • Inositol
  • Palladium
  • septacidin