Total Synthesis of Beshanzuenone D and Its Epimers and Abiespiroside A

Abstract

A unified and protecting-group-free six-step total synthesis of bisabolane-type sesquiterpenoid beshanzuenone D and its stereoisomers and abiespiroside A using S-(+)-carvone as a common chiral-pool building block is disclosed. This synthetic route features chemoselective allylic chlorination of carvone, Au­(I)-catalyzed cycloisomerization induced construction of furan from homopropargylic diol, substrate-controlled selective hydroxylation using Davis-oxaziridine, and dye-sensitized photo-oxidation (through 1O2) of hydroxyalkyl tethered furan to access oxaspirolactone as key transformations. A comprehensive set of NMR data along with DFT calculations, ECD spectra, and optical rotation measurements of the synthesized beshanzuenone D and its epimers were obtained to confirm absolute configurations.

Rational design and synthesis of l-carvone-derived 4-methyl-1,2,4-triazole-thioether/nanochitosan complexes as potent nanopesticides for sustainable and efficient herbicidal application

“…All the reagents and solvents used for the following procedures were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. (Shanghai, China) and directly used without pre-treatment. The key intermediates 2 and 4a–4u were prepared by reported methods, 33,34 which have also been described in the ESI† file, and the synthetic method of compounds 5a–5u is described as follows.…”

Synthesis, Antifungal Activity, and Molecular Simulation Study of L–Carvone‐Derived 1,3,4‐Oxadiazole‐Thioether Compounds

“…According to the reference, [34] 5.00 g (33.3 mmol) of L-carvone and 10.0 g (73.5 mmol) of NaH 2 PO 4 were dissolved in CH 2 Cl 2 (50 mL) and deionized water (50 mL), respectively, and then the two solutions were mixed under continuous stirring. Under ice-bath cooling, 50 mL of NaClO with active chlorine content of � 7.5 % was added dropwise into the obtained biphasic mixture.…”

Direct synthesis of oxaspirolactones in batch, photoflow, and silica gel-supported solvent-free conditionsviavisible-light photo- and heterogeneous Brønsted acid relay catalysis

“…1A). For example, the typical [4.4]-spiro scaffold exists in small natural products such as in the antimicrobial tetranorsesquiterpenoid lanceolactone A 2 and in the tricyclic cytotoxic pyrenolide D. 3 A ring-expanded oxaspirolactone, the spiro[4.5]-ring system, also occurs in the sesquiterpenoid beshanzuenone D, 4 a protein tyrosine phosphatase 1B (PTP1B) inhibitor that is associated with type-II diabetes and obesity treatment. A macrocyclic oxaspirolactone was also reported in 2018 with the isolation of the spirokermeline cyclophane.…”