Reações de fotooxigenação de pinenos em pinocarvonas, trans-pinocarveóis e mirtenal: uma abordagem em regime de fluxo contínuo

Abstract

In this work, a continuous flow protocol to prepare (-)-pinocarvone, (-)-trans- pinocarveol and (+)-myrtenal from (+)--pinene, (-)--pinene and -pinene through photooxygenation reactions was described. Furthermore, taking into account that the development of this protocol under continuous flow involves a large number of variables (flow, concentration, productivity, yield, oxygen pressure, and residence time), a new index was created to cover part of these variables (concentration, yield, and productivity), thus facilitating the analysis of the obtained data and the choice of the best and most productive reactional condition; this index was named as Efficiency. With the developed continuous protocol in hand, it was possible to perform the first description of the continuous synthesis of these derivatives on a multigram scale with the following isolated yields: (-)-pinocarvone (12.57 g, 73 %), (+)-pinocarvone (13.56 g, 76%), (-)-trans-pinocarveol (10.83 g, 61%) and (+)-trans-pinocarveol (10.66 g, 62%) in experiments performed in up to 24 h. In addition, promising results were obtained for the synthesis of (+)-myrtenal with a productivity of 9.05 g.day-1, a relevant result to be considered in future investigations.