Fuchs synthesis

Scheme 16. Jeong and Fuchs synthesis of diene 38 from hecogenin acetate.

Here is another alternative to oxidative phenolic coupling. Kathy Parker and her group (Brown University) described a synthesis of morphine that focuses on the same key bonds as seen in the Fuchs synthesis, but using totally different chemistry. The Parker plan was, once again, to construct the key C-N bond late in the synthesis from an intermediate of type 64. Parker also focused on initial construction of the same C-C bonds, but this time using a free radical addition-addition-elimination sequence beginning with a radical of type 65. The precursor of this radical (see 78 on Morphine-11) was to be an aryl bromide. This bromide was to be assembled from diol 66 and aryl bromide 67, structures that are similar to the pieces used in the Fuchs synthesis (49 and 54). 

Examples of a desulphonylation procedure on complex molecules are provided by Fuchs and coworkers199 who reported on a triply convergent synthesis of L-( —)-prostaglandin E2. The molecules can be classified as homoallylic sulphones and reductive desulphonylation was best achieved with a mixture of sodium methoxide and sodium borohydride in methanol, with yields being better than 90%, despite the complexity of the molecules involved (equation 87). 

The mechanism of the condensation in Part D probably involves thioformylation of the metallated isocyanoacetate followed by intramolecular 1,1-addition of the tautomeric enethiol to the isonitrile. This thi2izole synthesis is analogous to the formation of oxazoles from acylation of metallated isonitriles with acid chlorides or anhydrides. " Interestingly, ethyl formate does not react with isocyanoacetate under the conditions of this procedure. Ethyl and methyl isocyanoacetate have been prepared in a similar manner by dehydration of the corresponding N-formylglycine esters with phosgene and trichloromethyl chloroformate, respectively. The phosphoryl chloride method described here was provided to the submitters by Professor U. Schollkopf and is based on the procedure of Bohme and Fuchs. The preparation of O-ethyl thioformate in Part C was developed from a report by Ohno, Koi/.uma, and Tsuchihaski. " ... 

Fuchs, P.L. (2001) Increase in Intricacy - a Tool for Evaluating Organic Synthesis. Tetrahedron, 57, 6855-6875. 

Recent synthetic applications of the photochemical [2 -I- 2] cycloaddition of unsaturated sulfones have been noted. Musser and Fuchs have effected an intramolecular [2 -I- 2] addition of a 6-membered ring vinyl sulfone and a five-membered ring vinylogous ester in excellent yield, as part of a synthetic approach to the synthesis of the mould metabolite, cytochalasin C. The stereospecificity of the addition was only moderate, however, and later problems with this synthetic approach led to its abandonment. Williams and coworkers have used the facile [2 + 2] photoaddition of 73 and... 

For examples see (a) Silver(I) Carbonate on Celite, Fetizon M (2005) In Crich D, Fuchs PL, Molander G, Paquette LA (eds) Electronic encyclopedia of reagents for organic synthesis, Wiley, Sussex (b) Lafontaine JA, Provencal DP, Gardelli C, Leahy JW (2003) J Org Chem 68 4215... 

Fuchs S, Hollins AJ, Laue M, Schaefer UF, Roemer K, Gumbleton M, Lehr CM (2003) Differentiation of human alveolar epithelial cells in primary culture Morphological characterization and synthesis of caveolin-1 and surfactant protein -C. Cell Tissue Res 311 31—45... 

M. Fuchs, Bile Regulation of Hepatic Physiology 3, Regulation of Bile-acid synthesis Past Progress and Future Challenges, Am. J. Physiol. Gas-trointest. Liver Physiol., 2003, 284, 551-557. 

Domling A, Beck B, Fuchs T, Yazbak A (2006) Parallel synthesis of arrays of amino-acid-derived isocyanoamides useful as starting materials in IMCR. J Comb Chem 8(6) 872-880... 

Ollevier T, Nadeau E, Desyroy V (2009) Bismuth(III) trifluoromethanesulfonate. In Fuchs PL (ed) Electronic encyclopedia of reagents for organic synthesis (e-EROS). Wiley, Chichester, http //onlinelibrary.wiley.eom/o/eros/articles/m00959/frame.htinl. Accessed 22 Sep 2011... 

For a discussion of automated organic synthesis, see Frisbee Nantz Kramer Fuchs J. Am. Chem. Soc. 1984, 106, 7143. For an improved method, see Schnorrenberg Gerhardt Tetrahedron 1989, 45. 7759. 

Phase-transfer catalysts have been used instead of ZnCI, Landini Montanari Rolla Synthesis 1974, 37. " Fuchs Cole Can. J. Chem. 1975, 53, 3620. 

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