Alkylation of peroxyacids as a new method of peroxyester synthesis

Abstract

A new method for synthesis of short alkyl chain peroxyesters has been developed, which involves reaction of organic peroxyacids with alkyl trifluoromethanesulfonates, methyl chlorosulfonate, ethyl toluene-psulfonate, dimethyl sulfate and trialkyloxonium tetrafluoroborate performed under phase-transfer conditions.

Bioactive Diterpenes and Other Constituents of Croton steenkampianus

“…Treatment of 3 with acetic anhydride−pyridine yielded the triacetyl derivative, 4 (C 26 H 34 O 10 ), the IR spectrum of which was devoid of hydroxyl absorptions. In its 13 C NMR spectrum, the methyl carbon of one of the acetates (δ C 167.0, qC and 17.3, CH 3 ; δ H 2.08) appeared unusually shifted (δ C 17.3), indicating the presence of a peroxyacetate function, , which is also in agreement with molecular formula requirements. Thus, apart from the esterification of the hydroxyl groups at C-7 and C-15, the acetylation of 3 caused the hydrolysis of the 14-hemiacetal and subsequent acetylation of the resulting 6-hydroperoxide, as was also evidenced by the appearance of an additional ketone at C-14 (δ C 208.2, HMBC correlated with H-7, H-8, H 2 -12, and H-13, Table S1, Supporting Information) in the 13 C NMR spectrum of 4 .…”

Pd(ii) catalyzed ortho C–H iodination of phenylcarbamates at room temperature using cyclic hypervalent iodine reagents

“…Both electron-donating and electron-withdrawing substituents in the ortho, meta and para positions (-Me, -CF 3 , halides, ester and benzoyl groups, etc.) were well tolerated, leading to the formation of the desired products (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22). For instance, satisfactory yields were obtained with substrates which contained strong electron-withdrawing groups such as CF 3 and F (13,14).…”

“…Only one regioisomeric product was produced for meta-substituted substrates due to the steric discrimination (9)(10)(11)(12)(13)(14)(15)(16)22). As for para-substituted substrates, C-H halogenation exclusively occurred at the ortho-position of the carbamate groups give the expected iodinated compounds (17)(18)(19). For substrates with a potential competing ketone directing group, the corresponding products 20 could be obtained as well, in a yield of 64%.…”

The Chemistry of Peresters

“…Primary peresters have been synthesized via O ‐alkylation of peracids by sulfonates, sulfates, oxonium species, diazomethane or highly stabilized cation sources (trityl chloride) . Given that the peracid starting materials can be a challenge to handle, purify and store, this approach is mainly of value when acylation would be constrained by hydroperoxide volatility or reactivity, as in the case of a methyl perester.…”