Trimethyl-3-meth­oxy-4-oxo-5-triphenyl­phospho­ranyl­idene­cyclo­pent-1-ene-1,2,3-tricarboxyl­ate

The title compound, C30H27O8P (2), was formed as one of two products {(1) [Krawczyk et al. (2010 ▶). Acta Cryst. E66 (cv2752)] and (2)} in the reaction of dimethyl acetyl­enedicarboxyl­ate with triphenyl­phosphine. The mol­ecule of (2) consists of a five-membered carbocyclic ring. The P atom is a part of a triphenylphosphoranylidene substituent. In contrast to (1), the five-membered ring of (2) is planar, the r.m.s. deviation being only 0.009 (2) Å

Tetra­methyl 1,1,2-triphenyl-2H-1λ5-phosphole-2,3,4,5-tetra­carboxyl­ate

The title compound, C30H27O8P (1), was formed as one of two products {(1) and (2) [Krawczyk et al. (2010 ▶). Acta Cryst. E66 (cv2753)]} in the reaction of dimethyl acetyl­enedicarboxyl­ate with triphenyl­phosphine. The mol­ecule of (1) consists of a five-membered ring, in which the P atom is incorporated. One of the phenyl groups of the triphenyl­phosphine migrated to a vicinal C atom during the reaction. The five-membered ring of (1) is corrugated [r.m.s. deviation = 0.0719 (8) Å], whereas that in compound (2) is planar, the r.m.s. deviation being only 0.009 (2) Å

Studying the influence of substrates structure on the course and selectivity of alkene and alkyne metathesis

Metateza alkenów jaki i alkinów jest wysoce użytecznym narzędziem syntetycznym, ponieważ otrzymywane są w niej związki zawierające wiązania wielokrotne, które mogą być poddane kolejnym transformacjom prowadzącym do złożonych cząsteczek niejednokrotnie trudnych do uzyskania innymi metodami. Jednak zakres stosowalności metatezy krzyżowej jest ograniczony przez brak skutecznych metod kontroli selektywności tej reakcji. Dlatego opracowanie metod selektywnego prowadzenia metatezy krzyżowej stanowiło główny cel niniejszej rozprawy. Etapy pracy obejmowały: a) syntezę substratów do łączenia - pochodnych propynylobenzenu, b) łączenie substratów z łącznikiem przez grupy funkcyjne – w wyniku którego uzyskałam pochodne meta i para, c) łączenie substratów z łącznikiem poprzez utworzenie wiązania Si-C – w wyniku którego uzyskałam pochodne orto, d) testowanie związków w metatezie alkinów, e) obliczenia kwantowo-chemiczne, f) syntezę pochodnych disiloksanowych i testowanie ich w metatezie alkenów. Przeprowadzone badania, doprowadziły do opracowania przeze mnie struktur trzech różnych łączników, które zastosowałam w syntezie ośmiu różnych związków. Jeden z zaproponowanych łączników okazał się być użytecznym narzędziem w syntezie kombretastatyny A4. Możliwe są modyfikacje łącznika, które pozwolą na dostosowanie jego budowy do struktury innych substratów, które mają być poddane makrocyklizacji. Prowadząc reakcję metatezy zaobserwowałam, że miejsce przyłączenia łącznika w pierścieniu cząsteczki ma wpływ na jej reaktywność. W żadnym z zaproponowanych przypadków nie dochodziło do degradacji łącznika na etapie metatezy, co świadczy o właściwym doborze łączników do warunków reakcji. Sukcesem zakończyła się próba usunięcia po przeprowadzeniu reakcji metatezy jednego z łączników z cząsteczki. Okazało się, że zaproponowane połączenie jest na tyle labilne, że na etapie modyfikacji postmetatetycznych (podczas reakcji uwadarniania) ulega samorzutnemu usunięciu z cząsteczki. Badania teoretyczne doprowadziły do uzyskania informacji o strukturze przestrzennej i energii wybranych związków - zawierających i nie zawierających łączników silanowych. Pozwoliły również na ustalenie optymalnej długości łańcucha dla związków łączonych w różnych pozycjach. Zaproponowany łącznik można z powodzeniem stosować do łączenia substratów zarówno poprzez wiązania krzem-tlen jak i krzem-węgiel, a wnioski płynące z obliczeń teoretycznych stosować do optymalizacji jego długości w zależności od struktury stosowanych substratów.Both olefin and alkyne metathesis reactions constitute as very useful synthetic tools for the synthesis of compounds containing multiple bonds, which can be further transformed to highly complex molecules, that are often difficult to obtain by other methods. However, their applicability is limited by the lack of effective methods to control the selectivity of cross-metathesis reactions. Therefore, the development of selective cross-metathesis has constituted to be the main goal of this research, and included: a) the synthesis of substrates for linking – propynylbenzene derivatives b) linking substrates with linkers through functional groups, which has led to forming meta and para derivatives c) linking substrates with linkers by the formation of the carbon-silicon bond, resulting in forming orto derivatives d) testing compounds in alkyne metathesis reaction, e) quantum chemical calculations, f) synthesis of disiloxane derivatives and the investigation of their applicability within olefin metathesis. The conducted studies have led to the development of three different linkers, subsequently used in the synthesis of eight different compounds. One of the proposed linkers can be useful in the synthesis of Combretastatine A4. It is also possible to tailor the structure of linkers, so they can be adapted to the structure of substrates which shall be macrocyclized. Investigation of the metathesis reaction has revealed that the position of the linker in the molecule ring affects its reactivity. All linkers have been stable under the reaction condition, which confirms the proper choice of the latter with regard to the reaction conditions. Additionally, one of the linkers has been also successfully removed from the molecule after the metathesis reaction. This shows that the proposed linker is labile enough for the spontaneous removal from the molecule at the postmetathetical stage. Theoretical studies have allowed for a deeper insight into the structure and energy of selected compounds, with and without silane linkers. They have also allowed to determine the optimal chain length for compounds linked at different positions. The proposed linker can be successfully used for connecting substrates both by silicon-oxygen and silicon-carbon bonds. Moreover, the conclusions driven from theoretical calculations can be used to optimize the length of linker, depending on the structure of the used substrates

Development of cognitive processes inschoolchildren with learning difficulties inthe light ofanalysis ofWISC-R results

For several years now, noticeable has been a significant increase in the interest of psychologists – practitioners and scientists, of parents and teachers in the issues of dyslexia, dyscalculia, and other developmental disorders. Specific learning difficulties constitute one of the most prevalent causes of reporting children to psychological and pedagogic outpatient departments. The results of the performed studies enable inter- and intra-group comparisons as well as a global analysis of the structure of intellectual development in children with various learning difficulties. This leads to interesting conclusions and allows for comprehensive scientific discussions. The subject of the article is presentation of the results of studies and conclusions formulated according to them, about the structure of intellectual development of children with learning difficulties diagnosed in two psychological-pedagogic outpatient departments in Lublin region (Psychological-Pedagogic Outpatient Department No 5 in Lublin and PsychologicalPedagogic Outpatient Department No 2 in Zamość). Analysed were the results of the WISC-R scale obtained by schoolchildren from forms IV-VI of elementary schools and junior secondary schools in Lublin and schools of Zamość county. As scholastic difficulties constitute quite a comprehensive term, generally perceived as problems in acquisition of information and mastering school skills, in our study we take into account the following three groups of schoolchildren: with developmental dyslexia, intelligence lower than average, and specific disorders in arithmetic skills. The performed analyses are aimed at familiarization with the developmental level of the schoolchildren’s cognitive functions and their intellectual skills structure based on a three-factor analysis. Our studies continue earlier analyses, including more comprehensive research areas with larger groups

Comparison of a Full Food-Frequency Questionnaire with the Three-Day Unweighted Food Records in Young Polish Adult Women: Implications for Dietary Assessment

The food frequency questionnaire (FFQ) and the food record (FR) are among the most common methods used in dietary research. It is important to know that is it possible to use both methods simultaneously in dietary assessment and prepare a single, comprehensive interpretation. The aim of this study was to compare the energy and nutritional value of diets, determined by the FFQ and by the three-day food records of young women. The study involved 84 female students aged 21–26 years (mean of 22.2 ± 0.8 years). Completing the FFQ was preceded by obtaining unweighted food records covering three consecutive days. Energy and nutritional value of diets was assessed for both methods (FFQ-crude, FR-crude). Data obtained for FFQ-crude were adjusted with beta-coefficient equaling 0.5915 (FFQ-adjusted) and regression analysis (FFQ-regressive). The FFQ-adjusted was calculated as FR-crude/FFQ-crude ratio of mean daily energy intake. FFQ-regressive was calculated for energy and each nutrient separately using regression equation, including FFQ-crude and FR-crude as covariates. For FR-crude and FFQ-crude the energy value of diets was standardized to 2000 kcal (FR-standardized, FFQ-standardized). Methods of statistical comparison included a dependent samples t-test, a chi-square test, and the Bland-Altman method. The mean energy intake in FFQ-crude was significantly higher than FR-crude (2740.5 kcal vs. 1621.0 kcal, respectively). For FR-standardized and FFQ-standardized, significance differences were found in the mean intake of 18 out of 31 nutrients, for FR-crude and FFQ-adjusted in 13 out of 31 nutrients and FR-crude and FFQ-regressive in 11 out of 31 nutrients. The Bland-Altman method showed an overestimation of energy and nutrient intake by FFQ-crude in comparison to FR-crude, e.g., total protein was overestimated by 34.7 g/day (95% Confidence Interval, CI: −29.6, 99.0 g/day) and fat by 48.6 g/day (95% CI: −36.4, 133.6 g/day). After regressive transformation of FFQ, the absolute difference between FFQ-regressive and FR-crude equaled 0.0 g/day and 95% CI were much better (e.g., for total protein 95% CI: −32.7, 32.7 g/day, for fat 95% CI: −49.6, 49.6 g/day). In conclusion, differences in nutritional value of diets resulted from overestimating energy intake by the FFQ in comparison to the three-day unweighted food records. Adjustment of energy and nutrient intake applied for the FFQ using various methods, particularly regression equations, significantly improved the agreement between results obtained by both methods and dietary assessment. To obtain the most accurate results in future studies using this FFQ, energy and nutrient intake should be adjusted by the regression equations presented in this paper