The 12-membered lactone of 1 1-hydroxy-trans-8-dodecenoic acid is formed when the fungus Ceplialosporium recifei NRRL 5161 is grown on glucose solution.On a observt que la lactone a douze chainons de I'acide hydroxy-11 dodtcen-8-trans-oi'que se forme lorsque l'on fait croitre les champignons du Cep/~alosporium recifei NRRL 5161 dans des solutions de glucose.Canadian Journal of Chemistry, 49, 2029Chemistry, 49, (1971 Naturally occurring large-ring lactones were first described by Kerschbaum (1) in 1927. Since that time many more examples of this class of compounds have appeared, most of them macrolides. We now report the isolation of the monocyclic lactone 1 from a fungus.The organism appears to belong to the group Cephalosporium recifei, based on morphological studies and production of yellow pigment. The fungus was grown for 35 days on a shaken malt-glucose medium. Ether extraction of the whole culture liquor gave an average of 1.7 g of a viscous yellow oil A per liter of culture liquor. Hexane extraction of A at room temperature gave a 14% yield of nonpolar oil B, silicic acid column purification of which yielded a colorless mobile liquid C (7773, shown by g.1.c. to be 95% 1. Pure lactone 1 was obtained from fraction C in about 50% yield by preparative g.1.c.The structure of 1 was established as follows: elementary analyses and the molecular ion peak of mle 196 corresponded to a formula of C12H2,02. The i.r. spectrum showed a band at 1735 cm-', indicative of either a lactone or an ester, and a band at 975 cm-l, characteristic of a trans double bond. That the double bond was unconjugated was evident from the U.V. spectrum (end absorption only). Chemical studies are summarized in Scheme 1.It was first established that 1 is a lactone, rather than an ester, by saponification to 3, which was shown to be a 12-carbon acid by elementary analysis of its phenacyl derivative 4.Next, the size of the lactone ring was determined. The optical activity of 1 ([a],,25 + 73.2") required substitution on the lactone ring. The nature and the position of the substituent were arrived at by CrO, oxidation of 5 to the keto acid 6, which gave iodoform and the acid 7 on treatment with hypoiodite. Finally, the position of the double bond in 1 was ascertained by oxidation procedures (ozonolysis and KMn0,-HIO,), which led to 3-hydroxy-butyric acid (8) and suberic acid (9), both characterized as their benzhydrylamine salts.Information on the mass spectra of simple large-ring lactones appears to be meagre, the only two compounds studied so far being cyclopentadecanolide and 12-stearolactone (2). In our work the fragmentation patterns appear to be compatible with the assigned structures. The low resolution spectra of 1 (Fig. 1) and its dihydro derivative 2 (Fig. 2) are plotted along with the atomic compositions (determined by high resolution peak matching). Large peaks occur in the spectrum of 1 at 152 and 98, due probably to rearrangements involving opening of the lactone ring and cleavage at the Cl,-Cll bond to form the 152 peak and cleava...
