Barrett s approaches

Shortly after Barrett s publication of the successful approach to U-106305, Charette and Lebel reported the enantioselective synthesis of its non-natural enantiomer [12], and thereby further emphasised the power and the generality of their method. The same methodology was used to make the unnatural, all-trans septicyclopropane derivative 14 [10], the most highly cyclopropanated linear structure prepared to date. 

George Sand too favoured free translation, and would probably have supported Pichot s translation of Barrett s poem about her. Her translation of Shakespeare s As You Like It confirms the strength of the tradition of free translation, even as late as 1856. In her preface, Sand explains her approach, which was an attempt to adapt Shakespeare s text to French taste ... 

Woolf s emphases on education and experience as the necessary conditions for women s cultural and intellectual Hfe are a key aspect of her contributions to a sociology of culture, in which the environment and the social sphere become far more significant determinants of literary capacity and production than any concept of creativity as a purely personal property. Such materialism - as in her emphases in A Room of One s Own on the importance of financial independence and autonomous space - became central to the sociaHst-feminist approaches to Woolf of the 1970s, including Michele Barrett s collection of Woolf s essays. Women Writing, which significantly contributed to the reception of the feminist Woolf. 

A reevaluation of the approach to Barrett s esophagus has been proposed by S. Spechler and R. Goyal. Intestinal metaplasia may represent the critical variable of most pathologic significance. Unfortunately, the histologic recognition of the entity does not necessarily enable accurate prediction of its biologic behavior. 

Herrera, C.M. (1996). Floral traits and plant adaptation to insect pollinators a devil s advocate approach. In Floral Biology, eds. S. . H. Barrett and D. G. Lloyd, pp. 65-87. New York Chapman Hall. 

L. A. Kenna, L. Labbe, J. S. Barrett, and M. Pfister, Modeling and simulation of adherence approaches and applications in therapeutics. Am Assoc Pharm Sci J 7 E390-E267 (2005). 

Barrett, A. G. M., Lana, J. C. A., Tograie, S. J. Chem. Soc. Chem. Commun. 1980. 3(W Schmidtchen, F. P. Macrotricyclic ammonium salts enzyme like activity, in Chemical Approaches to Understanding Enzyme Catalysis, (ed. Green, B. S., Ashani, Y.,Chipman, D.)p. 315, Elsevier, Amsterdam 1982... 

The preceding reactions dealt with the use of chiral auxiliaries linked to the electrophilic arene partner. The entering nucleophile can also serve as a chiral controller in diastereoselective SjjAr reactions. This approach was successfully employed for the arylation of enolates derived from amino acids. To illustrate the potential of the method, two examples have been selected. Arylation of Schollkopf s bislactim ether 75 with aryne 77 as electrophilic arylation reagent was demonstrated by Barrett to provide substitution product 81 with good yield (Scheme 8.18) [62, 63]. Aryne 77 arises from the orf/jo-lithiation of 76 between the methoxy and the chlorine atom followed by elimination of LiCl. Nucleophilic attack of 77 by the lithiated species 78 occurs by the opposite face to that carrying the i-Pr substituent. Inter- or intramolecnlar proton transfer at the a-face of the newly formed carbanion 79 affords the anionic species 80. Subsequent diastereoselective reprotonation with the bulky weak acid 2,6-di-f-butyl-4-methyl-phenol (BHT) at the less hindered face provides the syn product 81. Hydrolysis and N-Boc protection give the unnatural arylated amino acid 82. The proposed mechanism is supported by a deuterium-labeling experiment. Unnatural arylated amino acids have found application as intermediates for the construction of pharmaceutically important products such as peptidomi-metics, enzyme inhibitors, etc. [64, 65]. 

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