A convergent synthetic approach to the tetracyclic core framework of khayanolide-type limonoids

• Zhiyang Zhang,
• Jialei Hu,
• Hanfeng Ding,
• Li Zhang and
• Peirong Rao

Beilstein J. Org. Chem. 2025, 21, 926–934, doi:10.3762/bjoc.21.75

• essential tertiary alcohol at C1. The β-hydroxylactone moiety (D ring) in 11 could be introduced through an intramolecular aldol condensation [35] of acetate 12. Ultimately, the preparation of 12 could be traced back to aldehyde 14 through 1,2-Grignard addition with an organomagnesium reagent [36] prepared

• % brsm). Since the newly created configuration at C30 was inconsequential, an intramolecular aldol reaction was directly carried out by treatment with LiHMDS to furnish β-hydroxylactone, which could be converted to dienone 11 through TPAP oxidation. Having secured 11, we proceeded to evaluate the pivotal

Rhodium-catalyzed intramolecular reductive aldol-type cyclization: Application for the synthesis of a chiral necic acid lactone

• Motoyuki Isoda,
• Kazuyuki Sato,
• Kenta Kameda,
• Kana Wakabayashi,
• Ryota Sato,
• Hideki Minami,
• Yukiko Karuo,
• Atsushi Tarui,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2022, 18, 1642–1648, doi:10.3762/bjoc.18.176

• structural component of the pyrrolizidine alkaloid monocrotaline. Keywords: β-hydroxylactone; intramolecular reductive aldol cyclization; necic acid lactone; rhodium catalyst; Introduction Carbon–carbon bond-forming reactions are among the most important reactions in the synthetic chemistry toolbox and the