Biodegrability of high density polyethylene film (HDPE) and low density polyethylene film (LDPE) both containing a balance of antioxidants and pro-oxidants was studied with defined microbial strains particularly with Rhodococcus rhodochrous and Nocardia asteroides in mineral medium. After an abiotic pre-treatment consisting of photooxidation and thermo-oxidation corresponding to about 3 years of outdoor weathering the samples were inoculated, incubated up to 200 days and during the period their metabolic activities were followed by measuring adenosine triphosphate content. Simultaneously the cultures were also monitored by optical microscopy and FTIR spectroscopy. The first initial phase of fast growth caused by the presence of low molecular extractable compounds was followed by a long period of stabilized metabolic activity suggesting that microorganisms continued to gain energy from the substrate but evidently at a much slower rate. Complementary analysis performed at the end of incubation revealed that during the experiment time biodegradation processes probably affected surface layer of materials onl

The access to several benzo[f]perhydroisoindolic analogues of farnesyltransferase inhibitors from a single dienic precursor is reported. An initial [4 + 2] cycloaddition between diphenylisobenzofuran6 and pyrrolines 11, 14, and 15 led to either the syn or the anti isomers, depending on the mode of activation of the cycloaddition. The syn diastereomers were isolated in 90% de under 12 kbar at room temperature, while their anti counterparts were obtained with the same selectivity by warming the reaction mixture to 110 degrees C in toluene at atmospheric pressure. Both syn and anti adducts were separately N-deprotected, and the resulting amines reacted with an activated ester derived from the acid (20) to afford the final targets (5). Two new analogues (5a and 5b) of the FT inhibitor RPR 130401 were thus synthesized in a mere three-step synthetic scheme with overall yields from 30 to 60%.

A new stereocontrolled synthetic pathway to 1,2,4-trioxygenated 1,3-dienes from pyruvic aldehyde dimethyl acetal (14a) is described. Reacting the cyclohexylamine-derived imine of this starting material with chloroalkyl ethers under basic conditions affords ketoacetals 18-20, which were then transformed into eight different enoxysilanes 12. A delta-elimination triggered by tert-butyllithium yields 1,2,4-trioxygenated dienes 13. Increasing the bulkiness of the silyloxy group or that of the acetal moiety leads stereoselectively to the (1E,3E) or (1Z,3E) isomers of 13, respectively. Hyperbaric [4 + 2] cycloadditions between 13 (13c, 13d, 13g) and N-methylmaleimide or methyl- and phenylacrylates give access to the expected cycloadducts with fine stereo- and regiocontrol.