Ultrasound in natural products synthesis: applications to the synthesis of histrionicotoxin via nitroalkanal acetals.
Ultrasound promoted the Kornblum reaction of silver nitrite or sodium nitrite with haloalkyl acetals to afford the corresponding C-nitro compounds. The acetalprotected nitro compounds were used as reactants in a 'double Henry' reaction to produce the key intermediate nitrocyclohexane diol with a masked aldehyde side chain. The nitrodiol was then subjected to an ultrasound-promoted one-pot/single operation sequence involving a reduction deprotection followed by a cyclization-reduction. The entire sequence provided the core spiropiperidine substructure of the histrionicotoxins.
Fitch
R W
RW
Department of Chemistry, University of Louisville, KY 40292, USA.
Luzzio
F A
FA
D000080:Acetals; D000664:Amphibian Venoms / Q000138:chemical synthesis* / Q000737:chemistry; D000818:Animals; D001001:Anura; D007202:Indicators and Reagents; D015394:Molecular Structure; D014465:Ultrasonics
D000080:Acetals; D000664:Amphibian Venoms; D007202:Indicators and Reagents; C007948:histrionicotoxin