Enzyme-Mediated Synthesis of (S)- and (R)-Verapamil

Enzyme-Mediated Syntheses of the Enantiomers ofγ-Irones

“…Hydrolysis of ()-5, followed by manganese(IV) oxide oxidation afforded (À)-trans-g-irone (À)-3b with an [a] 20 D À 81 (c 1, CH 2 Cl 2 ), a chemical purity of 99% ( [18]: we thus assumed that acetate ()-5 had (R) configuration at C(9). As ()-5 is the precursor of (À)-3b, (S) configuration was assigned to both C(2) and C(6).…”

Enzyme-Mediated Syntheses of the Enantiomers ofγ-Irones

“…Hydrolysis of ()-5, followed by manganese(IV) oxide oxidation afforded (À)-trans-g-irone (À)-3b with an [a] 20 D À 81 (c 1, CH 2 Cl 2 ), a chemical purity of 99% ( [18]: we thus assumed that acetate ()-5 had (R) configuration at C(9). As ()-5 is the precursor of (À)-3b, (S) configuration was assigned to both C(2) and C(6).…”

Multinuclear NMR and diffusion studies of quaternary amine‐based ionic liquids

“…Although 14 N is NMR active and has a high isotopic natural abundance (99.6%), reports of 14 N NMR of ILs in the literature is limited. [7,8] This is because 14 N nucleus has a large quadrupolar moment that interacts with the electric field gradient around it to produce a substantial quadrupolar coupling. This broadens the signal to the extent that it becomes unobservable.…”

Kinetic resolution of (E)-4-(2′,5′-dimethylphenyl)-but-3-en-2-ol and (E)-4-(benzo[d][1′,3′]dioxol-5′-yl)-but-3-en-2-ol through lipase-catalyzed transesterification

“…Brenna et al carried out the transesterification of (Z)-3-(3,4-dimethoxyphenyl)-1,4-dimethylpent-2-enol using Amano from B. cepacia and the reaction was very slow: after 108 h reaction time, the conversion was only 34% and the ee of remaining alcohol was only 47%. 15 The reaction conditions applied in our studies led to the successful resolution of alcohols with 2,5-dimethylsubstituted phenyl ring or benzodioxolane ring within only 1 h or 2 h. We have reported previously similar short reaction times and excellent enantiopurity of the products during transesterification of (E)-4-phenyl-and 4-(4 0 -methylphenyl)but-3-en-2-ol by CAL-B under the same conditions. 21…”

Enzyme-Mediated Syntheses of the Enantiomers ofγ-Irones

“…Hydrolysis of ()-5, followed by manganese(IV) oxide oxidation afforded (À)-trans-g-irone (À)-3b with an [a] 20 D À 81 (c 1, CH 2 Cl 2 ), a chemical purity of 99% ( [18]: we thus assumed that acetate ()-5 had (R) configuration at C(9). As ()-5 is the precursor of (À)-3b, (S) configuration was assigned to both C(2) and C(6).…”

Multinuclear NMR and diffusion studies of quaternary amine‐based ionic liquids

“…Although 14 N is NMR active and has a high isotopic natural abundance (99.6%), reports of 14 N NMR of ILs in the literature is limited. [7,8] This is because 14 N nucleus has a large quadrupolar moment that interacts with the electric field gradient around it to produce a substantial quadrupolar coupling. This broadens the signal to the extent that it becomes unobservable.…”

Kinetic resolution of (E)-4-(2′,5′-dimethylphenyl)-but-3-en-2-ol and (E)-4-(benzo[d][1′,3′]dioxol-5′-yl)-but-3-en-2-ol through lipase-catalyzed transesterification

“…Brenna et al carried out the transesterification of (Z)-3-(3,4-dimethoxyphenyl)-1,4-dimethylpent-2-enol using Amano from B. cepacia and the reaction was very slow: after 108 h reaction time, the conversion was only 34% and the ee of remaining alcohol was only 47%. 15 The reaction conditions applied in our studies led to the successful resolution of alcohols with 2,5-dimethylsubstituted phenyl ring or benzodioxolane ring within only 1 h or 2 h. We have reported previously similar short reaction times and excellent enantiopurity of the products during transesterification of (E)-4-phenyl-and 4-(4 0 -methylphenyl)but-3-en-2-ol by CAL-B under the same conditions. 21…”

Enzyme-Mediated Syntheses of the Enantiomers ofγ-Irones

“…Hydrolysis of ()-5, followed by manganese(IV) oxide oxidation afforded (À)-trans-g-irone (À)-3b with an [a] 20 D À 81 (c 1, CH 2 Cl 2 ), a chemical purity of 99% ( [18]: we thus assumed that acetate ()-5 had (R) configuration at C(9). As ()-5 is the precursor of (À)-3b, (S) configuration was assigned to both C(2) and C(6).…”

Multinuclear NMR and diffusion studies of quaternary amine‐based ionic liquids

“…Although 14 N is NMR active and has a high isotopic natural abundance (99.6%), reports of 14 N NMR of ILs in the literature is limited. [7,8] This is because 14 N nucleus has a large quadrupolar moment that interacts with the electric field gradient around it to produce a substantial quadrupolar coupling. This broadens the signal to the extent that it becomes unobservable.…”

Kinetic resolution of (E)-4-(2′,5′-dimethylphenyl)-but-3-en-2-ol and (E)-4-(benzo[d][1′,3′]dioxol-5′-yl)-but-3-en-2-ol through lipase-catalyzed transesterification

“…Brenna et al carried out the transesterification of (Z)-3-(3,4-dimethoxyphenyl)-1,4-dimethylpent-2-enol using Amano from B. cepacia and the reaction was very slow: after 108 h reaction time, the conversion was only 34% and the ee of remaining alcohol was only 47%. 15 The reaction conditions applied in our studies led to the successful resolution of alcohols with 2,5-dimethylsubstituted phenyl ring or benzodioxolane ring within only 1 h or 2 h. We have reported previously similar short reaction times and excellent enantiopurity of the products during transesterification of (E)-4-phenyl-and 4-(4 0 -methylphenyl)but-3-en-2-ol by CAL-B under the same conditions. 21…”