Chemistry of 1,2,4-Trioxanes: Metal-Induced Deoxygenation and Rearrangement of the 1,2,4-Trioxane Obtained by Photooxidation of β-Ionone

Abstract

D e o x y g e n a t i o n a n d R e a r r a n g e m e n t o f t h e 1 , 2 , 4 -T r i o x a n e O b t a i n e d b y P h o t o o x i d a t i o n o f b-IononeAbstract: The reactivity of 2,2,6,8-tetramethyltricyclo(6.2.2.0 1,6 )dodecene (2) toward different metal salts has been explored. In the presence of Fe(II), Sn(II) and Ce(IV) ions, compound 2 underwent a rearrangement process to afford acyclic triketones Z-3 and E-3. The action of Zn powder in acetic acid resulted in an unexpected formation of furan 4 in high yield.

Norterpenoids and Related Peroxides from the Formosan Marine Sponge Negombata corticata

“…The sponge N. corticata was subjected to extraction with EtOH. Fractionation of the lipophilic extract by repeated silica gel column chromatography and final purification using normal-phase HPLC afforded six new ( 4 − 9 ) and three known compounds ( 1 − 3 ) along with 6,6-dimethylundecane-2,5,10-trione ( 10 ), which was isolated for the first time from a natural source . The new compounds were given the trivial names negombatoperoxides A−D ( 4 − 7 ), negombatodiol ( 8 ), and negombatolactone ( 9 ).…”

“…Biogenetically, 10 might be derived from oxidative cleavage of epimuqubilin A at the C-9/C-10 and C-13/C-14 double bonds. This compound was isolated for the first time from a natural source …”

“…Fractionation of the lipophilic extract by repeated silica gel column chromatography and final purification using normal-phase HPLC afforded six new (4-9) and three known compounds (1-3) along with 6,6-dimethylundecane-2,5,10-trione (10), which was isolated for the first time from a natural source. 27 The new compounds were given the trivial names negombatoperoxides A-D (4-7), negombatodiol (8), and negombatolactone (9). The known compounds were identified as (+)-nuapapuin B (1), 19 (+)-nuapapuin B methyl ester (2), 19 and (+)-aikupikoxide C (3).…”

Structural characterization of strained oxacycles by 13C NMR spectroscopy

“…1,2 Due to their peroxidic nature, analogous to the pharmacophore of the potent antimalarial compound artemisinin, 1,2,4-trioxanic compounds have been the focus of great synthetic activity and several aspects of their fundamental chemical reactivity are currently under investigation. 3,4 During our studies directed to identifying mild and synthetically useful transformations of 1, 5 heterogeneous catalytic hydrogenation conditions were used to examine the chemoselectivity of the reduction process and to test primarily peroxy bond compatibility. The reduction of 1a-g affords products containing the 2,3,5-trioxabicyclo[2.2.2]octane and 2,7-dioxabicyclo[2.2.1]heptane units 2a-g and 3a-g, respectively, that can not readily be distinguished by means of spectroscopic techniques.…”

Domino Self-Sensitized Photooxygenation of Conjugated Dienones for the Synthesis of 1,2,4-Trioxanes

“…From an organic synthesis viewpoint, 1,2,4-trioxanes have been shown to be valuable as intermediates for the preparation of diverse heterocyclic scaffolds by the use of a variety of developed rearrangement and reductive processes . On the other hand and with regard to their preparation, many methodologies have been made available during the past decades primarily triggered by the need of new drug candidates .…”