Photooxygenation of a Microbial Arene Oxidation Product and Regioselective Kornblum–DeLaMare Rearrangement: Total Synthesis of Zeylenols and Zeylenones

Abstract

We report the enantioselective total syntheses of zeylenol (+)‐1, as well as its congeners (−)‐7 and 16, and of 3‐O‐debenzoylzeylenone 28. To this end, a new variant of the Kornblum–DeLaMare rearrangement, which utilises neighbouring‐group participation to impart regioselectivity, has been developed. The approach employs photooxygenation of building blocks derived from a microbial arene oxidation product.

Chemoenzymatic Synthesis of Pleiogenone A: An Antiproliferative Trihydroxyalkylcyclohexenone Isolated from Pleiogynium timorense

“…This diol serves as a convenient starting material for the synthesis of various natural products . Of the compounds pictured in Scheme only 4 has been recently synthesized by Lewis and by us . A synthesis of xylosmin is ongoing in our group at the present time .…”

Isolation and Synthesis of Novel Meroterpenoids from Rhodomyrtus tomentosa: Investigation of a Reactive Enetrione Intermediate

“…We believe that endoperoxide 13 b displays heightened reactivity because of the syn ‐stereochemical relationship of the α‐peroxy hydroxy group and the α‐peroxy methine hydrogen (Scheme b) . The more reactive endoperoxide ( 13 b ) may undergo formal, directed Kornblum–DeLaMare rearrangement to afford 14 . This intermediate can then react with caryophyllene to afford 5 – 11 .…”

Production of enantiopure β-amino-γ-hydroxyesters from benzoic acid by a selective formal aminohydroxylation

“…[1][2][3][4][5][6][7] Although the clear majority of synthetic examples are derived from diols obtained by the Toluene Dioxygenase enzymatic complex, dienediol 1 obtained by the ipso, ortho cisdihydroxylation of benzoic acid by Benzoate Dioxygenase (expressed in the mutant Ralstonia eutropha B9) has been recently used by several research groups to produce biologically active natural products and/or advanced intermediates. (Scheme 1A) [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] Examples are found in the literature for the total synthesis of polyoxygenated materials from benzoic acid, such as (-)-idesolide, [10] (+)-grandifloracin, [9] piperenol B, [13] pleiogenone A [14] and, more recently, a formal approach to xylosmin and flacourtosides E and F. [20] Although the dienic system in 1 does not present any substituent to allow for the differentiation of both olefins, selective oxygenation of either center of the ring can be accomplished by selecting the appropriate sequence of reactions (osmylation, epoxidation, diol protection) as described by Myers et al in 2001. [25] Regarding the preparation of N-containing products, several examples are shown in the literature, such as the synthesis of inosaminoacids, [26] inosamines, [7] pyrrolidines, [12] and tetracyclines [8] from benzoic acid ( Figure 1A).…”