A chiral LC–MS strategy for stereochemical assignment of natural products sharing a 3-methylpent-4-en-2-ol moiety in their terminal structures

• Rei Suo,
• Raku Irie,
• Hinako Nakayama,
• Yuta Ishimaru,
• Yuya Akama,
• Masato Oikawa and
• Shiro Itoi

Beilstein J. Org. Chem. 2025, 21, 2243–2249, doi:10.3762/bjoc.21.171

• the stereochemical assignment of (+)-capsulactone (1). Keywords: chemical degradation; chiral LC–MS analysis; methyl 3-hydroxy-2-methylbutanoate; 3-methylpent-4-en-2-ol moiety; p-nitrobenzoyl ester; Introduction Configurational elucidation of natural products is essential for progress in diverse

• -hydroxy-2-methylbutanoate (3) [25][26]. We then explored LC–MS conditions for their separation. In our initial trial, the stereoisomeric mixture of 3 was successfully separated by preparative high performance liquid chromatography (HPLC) using a chiral column (data not shown). However, each stereoisomer

• –MS detection of the MPO-derived fragment and to achieve a separation of four candidate stereoisomers. To this end, methylation of commercially available methyl acetoacetate (2) and subsequent reduction of the ketone carbonyl group was carried out to prepare a mixture of four stereoisomers of methyl 3