Two new caprolactones, (R)-10-methyl-6-undecanolide (1) and (6R,10S)-10-methyl-6-dodecanolide (2), were identified in the lipid extract of a marine streptomycete (isolate B6007). Their structures were proposed on the basis of GC-MS experiments and proved by synthesis. The absolute configuration of the compounds was established by comparison of the natural and synthetic stereoisomers using chiral gas chromatography. These caprolactones show a moderate phytotoxicity and a promising activity against cancer cells with concomitant low general cytotoxicity.
Like an enzyme: Asymmetric hydrolysis of enolesters is accomplished by chiral phase‐transfer catalysts under biphasic base hydrolysis conditions. Stoichiometric reactions support the generation of a well‐organized chiral ammonium hydroxide species (Q+OH−).