Synthesis of polyhydroxyindolizidines from 5,6-dihydro-2H-pyran-2-one.
(1aR,5aR,5bS,6S,7S)-6,7-Di-tert-butoxy-5-oxo-pyrrolidino[1,2-b]isoxazolidino[4,5-c]tetrahydropyran (8) prepared by (1,3)-dipolar cycloaddition of the cyclic nitrone 6 derived from tartaric acid to 5,6-dihydro-2H-pyran-2-one (7) was transformed into indolizidine 11 via a sequence of reactions involving methanolysis of the lactone ring, intramolecular alkylation of the nitrogen atom promoted by a carbontetrabromide-triphenylphosphine mixture and hydrogenolysis of the N single bond O bond. Decarboxylation of 11 provided known 7-hydroxylentiginosine derivative 14, whereas oxidative decarboxylation gave indolizidine 15 structurally related to castanospermine.
Socha
D
D
Institute of Organic Chemistry of the Polish Academy of Sciences, PL-01-224 Warsaw, Poland.
Jurczak
M
M
Chmielewski
M
M
D000470:Alkaloids / Q000138:chemical synthesis*; D007212:Indolizines / Q000138:chemical synthesis* / Q000737:chemistry; D011753:Pyrones / Q000737:chemistry*; D054836:Indolizidines
D000470:Alkaloids; D007212:Indolizines; D011753:Pyrones; C063984:lentiginosine; C035094:indolizine; C037806:castanospermine; D054836:Indolizidines