SYNTHESIS OF DEOXY SUGAR ESTERS: A CHEMOENZYMATIC STEREOSELECTIVE APPROACH AFFORDING DEOXY SUGAR DERIVATIVES ALSO IN THE FORM OF ALDEHYDE.

A chemoenzymatic synthesis of deoxy sugar esters is described. The synthesis is based on the O-alkylation of carboxylic acid with 2-bromo-5-acetoxypentanal. The method allows treatment of hydroxy carboxylic acids without protection of alcoholic hydroxyl groups. Several stereoisomeric deoxy sugar esters were resolved (up to ee or de > 98%) using a lipase-catalyzed acetylation of hemiacetals that in certain cases afforded deoxy sugar derivatives in the form of aldehydes. The stereochemistry of the reactions was determined by the NMR spectra of mandelic acid derivatives

Privatização dos serviços de extensão rural: uma discussão (des)necessária?

O artigo analisa e discute o tema da privatização dos serviços de extensão rural, conforme apresentado na literatura internacional. Inicialmente, a temática é situada no horizonte das discussões sobre a chamada Reforma do Estado, que pautaram as agendas sobre o desenvolvimento desde a década de 1980. Na seqüência, apresenta-se como o tema foi e vem sendo discutido à luz da teoria econômica e se examinam experiências de privatização em âmbito internacional. A análise dessas experiências mostra que a agenda inicial da privatização previa que os serviços de extensão rural, que estavam sob responsabilidade do Estado, passassem a ser integralmente assumidos pelo setor privado. No entanto, foi identificada uma série de limitações a tal intento e passou-se a proliferar os argumentos em favor de arranjos de privatização em que o Estado mantém um importante papel. Assim, o exame das experiências de privatização internacionais permitiu constatar que elas seguiram diferentes orientações. Um conjunto de experiências foi orientado pela noção de "Estado Mínimo" e outro conjunto de experiências teve como referência o Estado fomentador dos atores privados. A privatização continua sendo um processo atual e relevante e, portanto, sua discussão é considerada necessária.<br>The article analyzes and discusses the privatization of the rural extension services according to international literature. To start with, the subject is set in the horizon of the debate of the so called State Reform, which determined the agenda for the development since the 1980's. Next, we show how the subject has been treated so far having the economic theory as background and we examine experiments of privatization at international level. The analysis of such experiments reveals that the early agenda for the privatization took for granted that the rural extension services - which were a responsibility of the State - would be held completely by the private sectors. However, a series of obstacles appeared and arguments for models of privatization in which the State has a main role spread over. Therefore, the exam of international experiments of privatization led to the conclusion that they followed different orientations. One set of experiments was oriented by the notion of the "Minimum State" while the other had for reference the State as a supporter for private action. The privatization is a current and relevant process and, therefore, the discussion about it is considered necessary

Tandem and Sequential Multi-Enzymatic Syntheses

Summary This chapter contains sections titled: •Production of Isorhamnetin 3-O-Glucoside in Escherichia coli Using Engineered Glycosyltransferase •Multienzymatic Preparation of (−)-3-(Oxiran-2-yl)Benzoic Acid •Enzymatic Synthesis of Carbohydrates from Dihydroxyacetone and Aldehydes by a One Pot Enzyme Cascade Reaction •Aldolase Based Multi-Enzyme System for Carbon[BOND]Carbon Bond Formation •Tandem Biocatalytic Process for the Kinetic Resolution of β-Phenylalanine and its Analogs •A Chemoenzymatic Synthesis of a Deoxy Sugar Ester of N-Boc-Protected L-Tyrosine •Electrochemical Systems for the Recovery of Succinic Acid from FermentationsPeer reviewe