Synthesis, photooxygenation, and Diels-Alder reactions of 1-methyl-4a,5,6,7,8,8a-trans-hexahydronaphthalene and 1,4a-dimethyl-4a,5,6,7,8,8a-trans-hexahydronaphthalene

Autoxidation of a C2-Olefinated Dihydroartemisinic Acid Analogue to Form an Aromatic Ring: Application to Serrulatene Biosynthesis

“…The observation of an allylic hydroperoxide intermediate is supported in experiments that involved 18 O 2 where an intermediate with the mass of [M + 36] ( m / z 269) was observed (see SI, Part 6). Furthermore, the photooxygenation of a similar diene system that lacks a carboxylic acid moiety has been reported to yield allylic hydroperoxide intermediates by Sasson and Labovitz …”

“…Furthermore, the photooxygenation of a similar diene system that lacks a carboxylic acid moiety has been reported to yield allylic hydroperoxide intermediates by Sasson and Labovitz. 41 Synthesis of 9,10-Dihydroserrulatene (38) to Investigate Aromatization to Serrulatene (11). Since 2,3didehydro-DHAA aromatized to compound 6 (Figure 7, 3 to 6), this autoxidation process was exploited toward understanding the biosynthesis of serrulatene from dihydroserrulatene (Figure 3B, 10 to 11).…”

Recent Developments in Singlet Molecular Oxygen Chemistry

“…Several recent studies have appeared on the reactions of various organic compounds with '02 : indenes [13], 1,2-dihydronaphthalenes [ 141, substituted hexahydronaphthalene [68], arene oxides [27], benzophenone oxime [S3], indols [7,66], and steroids [l].…”

Studies on Biomimetic Singlet Oxygen Oxidations: Application to the Synthesis of the Alkaloid Simulenoline

“…In this context, although attractive as a potential biomimetic approximation toward alkaloid 1 , an analysis of synthetic approaches toward natural products via singlet oxygen oxidations reveals that whenever a conjugated diene unit is present within a substrate as in 3 , [4 + 2] cycloadditions prevail (Figure B). − These examples not only seem to include electron-rich s - cis fixed cyclic dienes, as may be expected, but also acyclic dienes, heterodienes, and others. Interestingly, only during the synthesis of phomactin and brevetoxin via the intermediacy of α-pyran 4d and diene 4g , respectively, do the authors comment on the isolation of small amounts of side products due to competing singlet oxygen reactions other than [4 + 2] cycloadditions. , Due to our interest in the photooxygenation of 2 H -pyran and dienone valence isomers, − and taking into account that exceptions to this apparent trend can be found throughout the literature, − we became intrigued by the possibility of preparing alkaloid 1 in such a facile way. Herein we present our studies on the chemoselective reactivity of singlet oxygen, which culminated in a simple synthesis of alkaloid 1 and revealed the complex interplay of several factors that influence these oxidations.…”