66625-19-2

Usage

InChI:InChI=1/C10H12O5/c1-13-7-4-6(11)5-8(14-2)9(7)10(12)15-3/h4-5,11H,1-3H3

Upstream product

• 861530-64-5 2,6-dimethoxy-4-methoxycarbonyloxy-benzoic acid methyl ester 
• 136213-37-1 (1R^*,5R^*,6R^*)-6-carbomethoxy-4,6-dimethoxybicyclo<3.1.0>hex-3-en-2-one 
• 93652-78-9 4-(benzyloxy)-2,6-dimethoxybenzoic acid methyl ester 

Downstream Products

• 66625-16-9 4-Hydroxy-2,6-dimethoxy-3-trifluoromethylsulfanyl-benzoic acid methyl ester 
• 94622-74-9 4-(benzyloxy)-2,6-dimethoxybenzoic acid 
• 94253-01-7 3-Jod-4-benzyloxy-2,6-dimethoxy-benzoesaeure 
• 93816-43-4 3-Jod-4-benzyloxy-2,6-dimethoxy-benzoesaeure-methylester 
• 92553-84-9 Benzyl-<2-iod-3,5-dimethoxy-phenyl>-aether 
• 57290-94-5 Benzyl-<4-iod-3,5-dimethoxy-phenyl>-aether 
• 93652-78-9 4-(benzyloxy)-2,6-dimethoxybenzoic acid methyl ester 
• 84741-02-6 2,6-dimethoxy-4-hydroxybenzoic acid 

Relevant academic research and scientific papers

DPPH (=2,2-diphenyl-1-picrylhydrazyl=2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl) radical-scavenging reaction of protocatechuic acid esters (=3,4-dihydroxybenzoates) in alcohols: Formation of bis-alcohol adduct

Protocatechuic acid esters (=3,4-dihydroxybenzoates) scavenge ca. 5 equiv. of radical in alcoholic solvents, whereas they consume only 2 equiv. of radical in nonalcoholic solvents. While the high radical-scavenging activity of protocatechuic acid esters in alcoholic solvents as compared to that in nonalcoholic solvents is due to a nucleophilic addition of an alcohol molecule at C(2) of an intermediate o-quinone structure, thus regenerating a catechol (=benzene-l,2-diol) structure, it is still unclear why protocatechuic acid esters scavenge more than 4 equiv. of radical (C(2) refers to the protocatechuic acid numbering). Therefore, to elucidate the oxidation mechanism beyond the formation of the C(2) alcohol adduct, 3,4-dihydroxy-2-methoxybenzoic acid methyl ester (4), the C(2) MeOH adduct, which is an oxidation product of methyl protocatechuate (1) in MeOH, was oxidized by the DPPH radical (=2,2-diphenyl-1-picrylhydrazyl) or o-chloranil (=3,4,5,6-tetrachlorocyclohexa- 3,5-diene-1,2-dione) in CD3-OD/(D6)acetone 3:1). The oxidation mixtures were directly analyzed by NMR. Oxidation with both the DPPH radical and o-chloranil produced a C(2),C(6) bis-methanol adduct (7), which could scavenge additional 2 equiv. of radical. Calculations of LUMO electron densities of o-quinones corroborated the regioselective nucleophilic addition of alcohol molecules with o-quinones. Our results strongly suggest that the regeneration of a catechol structure via a nucleophilic addition of an alcohol molecule with a o-quinone is a key reaction for the high radical-scavenging activity of protocatechuic acid esters in alcoholic solvents.

Substituent Effects on the Photorearrangements of 4-Alkoxy-4-carbomethoxy-3-methoxy-2,5-cyclohexadien-1-ones

Enantiomerically enriched 4-carbomethoxy-3,4-dimethoxy-2,5-cyclohexadien-1-one (1) undergoes a completely diastereoselective (but not enantiospecific) type A photorearrangement at 366 nm to give 6-carbomethoxy-4,6-dimethoxybicyclohex-3-en-2-one (2) in 81 percent isolated yield.A chiral NMR shift study indicates that 1 undergoes partial loss of absolute configuration at C(4) during irradiation.Bicyclohexenone 2 is photostable at 366 nm but rearranges to its diastereoisomer 3 and phenols 4 and 5 at > 300 nm.It is proposed that ground-state conformational effects control the type A photoreactivity of 1 and that rearrangement to 2 occurs in accord with the principle of least motion in the transition states for rearrangements to diastereomerically related zwitterions 1a and 1b (Scheme III).The intramolecular 2 + 2 photocycloaddition of 4-carbomethoxy-3-methoxy-4-(1'-oxa-3'-butenyl)-2,5-cyclohexadien-1-one (9) gives a mixture of 7-oxatricyclodecenones 10 (58percent) and 11 (18percent), without interference from type A photoreactivity.