hyacinthacine-a2 and casuarine

hyacinthacine-a2 has been researched along with casuarine* in 1 studies

Other Studies

1 other study(ies) available for hyacinthacine-a2 and casuarine

Article	Year
SmI2-mediated radical cross-couplings of α-hydroxylated aza-hemiacetals and N,S-acetals with α,β-unsaturated compounds: asymmetric synthesis of (+)-hyacinthacine A2, (-)-uniflorine A, and (+)-7-epi-casuarine. The Journal of organic chemistry, 2011, Jun-17, Volume: 76, Issue:12 The SmI(2)-mediated radical coupling reactions of β-hydroxylated pyrrolidine/piperidine aza-hemiacetals 8 and 9 and N,S-acetals 6 and 33 with α,β-unsaturated compounds are described. This method allows a rapid access to β-hydroxylated pyrrolidines, piperidines, pyrrolizidinones, and indolizidinones. Starting from N,S-acetal 33 and via a common intermediate 27, the alkaloids hyacinthacine A(2) (2), uniflorine A (3, 6-epi-casuarine), and the unnatural epimer 7-epi-casuarine (37) have been synthesized in four and five steps with overall yields of 34%, 16%, and 13%, respectively. The radical mechanism of the coupling reactions has been confirmed by controlled experiments, which also allowed deducing the anionic mechanism in the coupling between N,S-acetal 6 and carbonyl compounds. This demonstrates that the mechanisms of these SmI(2)-mediated reactions are switchable from Barbier-type anionic to radical by cooperative action of BF(3)·OEt(2) and t-BuOH. Topics: Acetals; Alkaloids; Aza Compounds; Free Radicals; Hydroxylation; Indolizines; Iodides; Molecular Structure; Pyrroles; Pyrrolizidine Alkaloids; Samarium; Stereoisomerism	2011

Article

Year

SmI2-mediated radical cross-couplings of α-hydroxylated aza-hemiacetals and N,S-acetals with α,β-unsaturated compounds: asymmetric synthesis of (+)-hyacinthacine A2, (-)-uniflorine A, and (+)-7-epi-casuarine.

The Journal of organic chemistry, 2011, Jun-17, Volume: 76, Issue:12

The SmI(2)-mediated radical coupling reactions of β-hydroxylated pyrrolidine/piperidine aza-hemiacetals 8 and 9 and N,S-acetals 6 and 33 with α,β-unsaturated compounds are described. This method allows a rapid access to β-hydroxylated pyrrolidines, piperidines, pyrrolizidinones, and indolizidinones. Starting from N,S-acetal 33 and via a common intermediate 27, the alkaloids hyacinthacine A(2) (2), uniflorine A (3, 6-epi-casuarine), and the unnatural epimer 7-epi-casuarine (37) have been synthesized in four and five steps with overall yields of 34%, 16%, and 13%, respectively. The radical mechanism of the coupling reactions has been confirmed by controlled experiments, which also allowed deducing the anionic mechanism in the coupling between N,S-acetal 6 and carbonyl compounds. This demonstrates that the mechanisms of these SmI(2)-mediated reactions are switchable from Barbier-type anionic to radical by cooperative action of BF(3)·OEt(2) and t-BuOH.

Topics: Acetals; Alkaloids; Aza Compounds; Free Radicals; Hydroxylation; Indolizines; Iodides; Molecular Structure; Pyrroles; Pyrrolizidine Alkaloids; Samarium; Stereoisomerism

2011