Chiron Approaches

S. Hanessian, "Total Synthesis of Natural Products The Chiron Approach" (Pergamon Press, Oxford, 1983). 

For excellent discussions of the use of optically active starting materials in synthesis, see (a) Hanes-sian, S. The Total Synthesis of Natural Products. The Chiron Approach, Pergamon Press New York, 1983 (b) Scott, J.W. In Asymmetric Synthesis, Morrison, J.D. Scott, J. W., Eds., Academic Press San Diego, 1984, Vol. 4, p. 1. 

Hanessian, S., Pan, J., CarneU, A., Bouchard, H., Lesage, L. (1997) Total Synthesis of (—)-Reserpine Using the Chiron Approach. Journal of Organic Chemistry, 62, 465-473. 

Reviews (a) Omura, S. Yuki Gosei Kagaku Kyokaishi 1986, 44, 127 (b) Hanessian, S. In "Total Synthesis of Natural Products The Chiron Approach" Pergamon New York, 1983 Chapter 2 (c) Mori, K. In "The Total Synthesis of Natural Products" ApSimon, J, Ed. Wiley New York, 1981 Vol. 4, Chapter 1 (d) Seebach, D. Hungerbuhler, E. In "Modern Synthetic Methods" Scheffold, R., Ed. Otto Salle Verlag Frankfurt am Main, Germany, 1980, Vol. 2. 

S. Hanessian Total synthesis of natural products The chiron approach. Pergamon, 1983. 

Examples are the synthesis of prostaglandin F2 and erythronolide A (8) from D-glucose, by Stork [20] and Hanessian [19] and their coworkers, respectively, whose retrosynthetic pathways are shown in Schemes 9.9 and 9.10. For more details concerning this strategy, known as "the chiron approach", see the book by Hanessian [19]. 

S. Hanessian, "Total Synthesis of Natural Products The Chiron Approach", Pergamon Press, Oxford, 1983 see also, W.A. Szabo and H.T. Lee, Aldrichimica Acta 1980,13, 13. 

Aiming at the pyranose form of sugars, normal type hetero-Diels-Alder reactions were extensively used for the synthesis of functionally substituted dihydropyran and tetrahydropyran systems (5-10) (see routes A - D in the general Scheme 1) which are also important targets in the "Chiron approach" to natural product syntheses (2.) Hetero-Diels-Alder reactions with inverse electron demand such as a, p-unsaturated carbonyl compounds (l-oxa-1,3-dienes) as heterodienes and enol ethers as hetero-dienophiles, are an attractive route for the synthesis of 3,4-dihydro-2H-pyrans (11). 

Hanessian, S. Acc. chem. Res. 1979, 1 2, 159-165. Schmidt, R.R. Maier, M. Synthesis 1982, 747-748. Hanessian, S. "Total Synthesis of Natural Products The Chiron Approach" Pergamon Press Oxford 1983. Nogradi, M. "Stereoselective Synthesis" VCH Verlagsgesellschaft mbH D-6940 Weinheim 1987 and references cited therein. 

The stereoselective synthesis of carbohydrates from acyclic precursors is a research topic that has attracted considerable attention over the past decadeT Efforts in this area are easily justified and have maximum impact particularly when directed toward rare sugars or other polyhydroxylated molecules that are not conveniently accessed via classical "chiron" approaches.2 An underlying theme of such efforts, of course, is the development of practical synthetic methodology that will find broad application in the enantio- and diastereoselective synthesis of natural products, their analogues, and other compounds of biological interest. 

For a discussion of this approach to enantioselective synthesis, see S. Hanessian, Total Synthesis of Natural Products, the Chiron Approach, Pergamon Press, New York, 1983. 

A broader use of carbohydrates in this context has been treated by Hanessian in The Chiron Approach [9] and a recent book entitled Carbohydrate Building Blocks has just appeared [10]. 

Total Synthesis of Natural Products S. Hanes-sian. The Chiron Approach, Pergamon, Oxford... 

Tor books on the synthesis of optically active compounds starting from natural products, see Coppola. Schuster Asymmetric Synthesis Wiley New York. 1987 (amino acids as starting compounds) Hanessian Total Synthesis of Natural Products The Chiron Approach-, Pergamon Elmsford. NY, 1983 (mostly carbohydrates as starting compounds). For reviews, see Jurczak Pikul Bauer Tetrahedron 1986, 42, 447-488 Hanessian Aidrichimica Acta 1989, 22, 3-15 Jurczak Gol biowski Chem. Rev. 1989, 89, 149-164. 

For reviews see (a) R. J. Fenier and S. Middleton, The conversion of carbohydrates into functionalized cyclopentanes and cyclohexanes, Chem. Rev. 95 2779 (1993) (b) K. J. Hale, Monosaccharides Use in asymmetric synthesis of natural products, Rodd s Chemistry of Carbon Compounds. Second Supplement to the 2nd ed. (M. Sainsbury, ed.), Elsevier, Amsterdam, 1993, Vol. 1E/F/G, pp. 315-435 (c) T. D. Inch, Formation of convenient chiral intermediates from carbohydrates and their use in synthesis, Tetrahedron 40 3161 (1984) (d) S. Hanessian, Total Synthesis of Natural Products The Chiron Approach Pergamon, New York, 1983. 

Hanessian, S 1983, Total Synthesis of Natural Products The Chiron Approach, Pergamon Press Oxford Hankinson, B, Heaney, H, Sharma, R. P 1972, J Chem Soc Perkin Trans I 1972, 2372 Hardcastle, G A., Jr, Johnson, D A, Panetta, G A, Scott, A I, Sutherland, S A 1966, J Org Chem. 

Corey (E.J Corey Pure Appl Chem 1969,14, 30) introduced the term synthon in 1969 when he published his innovative strategies for the construction of complex molecules by considering a retrosynthetic analysis. Later on, Hanessian s (Total Synthesis of Natural Products The Chiron Approach Pergamon Press, 1983) introduction in 1983 of the term Chiron referring to chiral synthons became the general strategy of carbohydrate like symmetry in new molecular targets of many natural products. 

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