Synthetic model of a new deoxybenzoin derivative from Deguelia hatschbachii A.M.G. Azevedo

In this paper we describe the synthesis of 2´,4´-dimethoxy-8-(propyl-2-one)-deoxybenzoin, a new compound employed as a model for the comparison with the respective spectral data for 6',4-dihydroxy-3'-(3,3- dimethylallyl)-2",2"-dimethylchromene(5",6":5',4')-2'-methoxy-8-(propyl-2-one) deoxybenzoin, recently isolated from Deguelia hatschbachii A.M.G. Azevedo. Both compounds have a "propyl-2-one" group attached to C-8 of the deoxybenzoin skeleton, for which there is no precedent in the literature. The Friedel-Crafts reaction of 1,3-dimethoxybenzene with phenylacetyl chloride furnished 2´,4´-dimethoxydeoxybenzoin, that after reaction with allyl bromide gave 2´,4´-dimethoxy-8-(allyl)-deoxybenzoin . Wacker oxidation gave the desired model compound in 15% overall yield. The corresponding spectral data reinforced the structure previously determined for the natural product.

Óleos voláteis de espécies de Myrcia nativas do Rio Grande do Sul

Essential oils from M. richardiana, M. arborescens, M. selloi, M. oligantha, M. rostrata, M. lajeana, M. obtecta, M. pubipetala and M. hatschbachii were obtained by hydrodistillation and analyzed by GC and GC/MS. Sixty-seven compounds have been identified ranging from 90-99% of the oil contents. All analyzed species were rich in cyclic sesquiterpenes (66-99%), mainly those from the cadinane, caryophyllane and germacrane cyclization pathway, among them b-caryophyllene, germacrene D, bicyclogermacrene, d-cadinene, spathulenol, caryophyllene oxide, globulol and a-cadinol. The acyclic sesquiterpene series was well represented by M. lajeana (32.1%), with 25,3% of (E)-nerolidyl acetate.

Three new species of Eugenia sect. Racemosae (Myrtaceae) from the cerrados of the state of Mato Grosso, Brazil

Three new species of Eugenia sect. Racemosae (Myrtaceae) from cerrado vegetation of central region in Brazil are described and illustrated. They are: Eugenia hatschbachii Mazine, Eugenia mattogrossensis Mazine and Eugenia glabrescens Mazine. Data on the geographic distribution and habitat are given for the new taxa.