Studies directed toward the synthesis of FS-2: observations on the fragmentation of cyclobutylcarbinyl radicals

Phomanones A-C From Phoma sp. HDN16-618: A Mariana Trench Fungus

“…Its molecular formula was established as C 8 H 12 O 2 S on the basis of the protonated molecular peak at m/z 173.0628 [M+H] + in its High Resolution Electrospray Ionization Mass Spectroscopy (HRESIMS), requiring 3 degrees of unsaturation. The 1D and 2D NMR data (Table 1) of 1 were similar to the known compound 4 , 8,9 revealing the existence of a 2-hydroxymethyl-3-methylcyclopent-2-enone moiety, which was further confirmed by the 1H-1H Correlation Spectroscopy (COSY) and 1H Detected Heteronuclear Multiple Bond Correlation (HMBC) correlations (Figure 2). The additional signals were assigned to a thiomethyl group moiety attached to C-4 on the basis of the key COSY correlations of H-4 (δ H 3.88)/H 2 -5(δ H 2.81, 2.32) and the HMBC correlations from H 3 -8 (δ H 1.81) to C-4 (δ C 45.9).…”

The Application of Cyclobutane Derivatives in Organic Synthesis

“…In addition to the synthesis of the sesquiterpene FS-2, Ziegler et al reported the ring cleavage of the cyclobutoxy radical 490 affording a cyclohexene-annelated cycloheptanone 491 . This bicyclic ketone was obtained in 80% yield as the ring enlarged product starting from the appropriate bromoalkyl-substituted bicyclo[4.2.0]oct-2-en-8-one 489 upon treatment with tributyltin hydride/AIBN 172 …”

Cyclopentenones, Scaffolds for Organic Syntheses Produced by the Endophytic Fungus Mitosporic Dothideomycete sp. LRUB20

“…2-Hydroxymethyl-3-methylcyclopent-2-enone ( 1 ) was obtained as a colorless oil. Comparison of the 1 H and 13 C spectra of 1 with those of 2-hydroxymethyl-3-methylcyclopent-2-enone, a common chemical scaffold in organic synthesis, suggested that 1 was 2-hydroxymethyl-3-methylcyclopent-2-enone. It should be noted that δ C (173.6) of the C-3 double bond in 1 was significantly shifted downfield, similar to the carbonyl resonances for carboxylic acids or esters.…”

“…Due to interesting antibacterial and antifungal activities reported, synthetic chemists have shown interest in the syntheses of cyclopentenones , Green chemistry may play a crucial role in future chemical syntheses, and the use of microbial building blocks for subsequent use in organic syntheses provides fundamental advantages in comparison to chemical methods . The term “white biotechnology” has been recently introduced for microbial production of building blocks, and various 2-oxocarboxylic acids are examples of chemical scaffolds from microbial fermentation .…”