404909-82-6Relevant articles and documents
Chemoenzymatic synthesis of deoxy analogues of the DNA topoisomerase II inhibitor eleutherin and the 3C-protease inhibitor thysanone
Bachu, Prabhakar,Sperry, Jonathan,Brimble, Margaret A.
, p. 4827 - 4834 (2008/09/21)
The asymmetric synthesis of (-)-9-demethoxyeleutherin 6, (+)-9-demethoxyeleutherin 7 and (+)-7,9-deoxythysanone 8 has been achieved using a microwave assisted kinetic resolution of racemic alcohol 11 with Novozyme 435 as the key step.
The influence of microwave irradiation on lipase-catalyzed kinetic resolution of racemic secondary alcohols
Bachu, Prabhakar,Gibson, Jennifer S.,Sperry, Jonathan,Brimble, Margaret A.
, p. 1618 - 1624 (2008/02/11)
The influence of microwave irradiation on the Novozyme 435 (Candida antarctica lipase) catalyzed kinetic resolution of secondary alcohols with different functional groups was studied in comparison to the use of conventional heating at 60 °C. p-Chlorophenyl acetate was used as an acyl donor and toluene as the solvent. (±)-1-Phenyl-1-propanol 1, (±)-1-(4-bromophenyl)-propan-1-ol 3, (±)-1-phenylbut-3-en-1-ol 5 and (±)-3-bromo-2-(2-hydroxypropyl)-1,4-dimethoxynaphthalene 7 were successfully resolved into their (S)-alcohols and (R)-esters, respectively, in good enantiomeric excess. Resolution of (±)-ethyl-5-(4-methoxybenyloxy)-3-hydroxypentanoate 9 afforded its (R)-alcohol and (S)-ester using this method. In addition, microwave-assisted lipase transesterification of meso-symmetric diol 11 effected desymmetrization to ester 12 with high enantiomeric excess. In all cases studied, the conversion value for the microwave-assisted lipase kinetic resolution of secondary alcohols was higher than that obtained using conventional heating.
Stereoselective synthesis of deoxy analogues of the 3C-protease inhibitor thysanone
Brimble, Margaret A,Elliott, Richard J.R
, p. 183 - 189 (2007/10/03)
The synthesis of racemic 7,9-dideoxythysanone 9 was achieved starting from allylnaphthalene 5 via epoxidation and reduction to bromoalcohol 7. Subsequent lithiation of the bromide and quenching with DMF afforded lactol 8 which underwent clean oxidative demethylation to racemic 6,8-dideoxythysanone 9. The synthesis of (1R,3S)-(+)-7,9-dideoxythysanone 9 was then achieved albeit in low ee, starting from (R)-epoxide 6 which in turn was obtained via Sharpless asymmetric dihydroxylation of allylnaphthalene 5. An improved asymmetric synthesis of (1S,3R)-(+)-7,9-dideoxythysanone 9 in 72% ee was then accomplished starting from (R)-bromoalcohol 7 which was obtained via asymmetric reduction of ketone 12 using a modified chiral oxazaborolidine. The key ketone 12 in turn was prepared by Wacker oxidation of allylnaphthalene 5.