Danishefsky, Samuel

Fischer projections of, 980 Dacron, structure of, 819 Danishefsky, Samuel, 1002 Darzens reaction. 913 DCC (dicyclohexylcarbodiimide),... 

Yang Zhi-Qiang, Geng Xudong, Solit David, Pratilas Christine A, Rosen Neal, Danishefsky Samuel J, J. Am.. Chem. Soc., 2004,126, 7881. 

Samuel Danishefsky s group at the Sloan Kettering Institute for Cancer Research in New York has also been active in the synthesis of the natural epothilones and biologically active analogs. One of their syntheses also used the olefin metathesis reaction (not shown). The synthesis in Scheme 13.62 used an alternative approach to create the macrocycle, as indicated in the retrosynthetic scheme. The stereochemistry at C(6), C(7), and C(8) was established by a TiCl4-mediated cyclocondensation (Step A). The thiazole-containing side chain was created by reaction sequences F and G. The... 

Samuel J. Danishefsky, Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, NY 10021 and Department of Chemistry, Havemeyer Hall, Columbia University, New York, NY 10027... 

Other alkcnes in the substrate, and especially other alkynes, will react with the Ru catalyst. Samuel Danishefsky, of Columbia University and Sloan-Kettering Institute, recently completed (Organic Lett. 2004,6,413) the total synthesis of the antimalarial and antitumor agent aigialomycin D. For the Ru-mediated macrocyclization of 4 to 5, the alkyne in the molecule was protected as the dicobalt octacarbonyl adduct. After the cyclization, the alkyne was deprotected by brief exposure to ceric ammonium nitrate. 

Samuel Danishefsky of Columbia University has also described (J. Am. Chem. Soc. 2005, 127, 8298) a total synthesis of 1, starting from the pyroglutamate derivative 10. Conjugate addition followed by alkylation established the lactam framework. Intramolecular cyclization of 12 gave 13, establishing the aminated quaternary center. The oxygenated quaternary center was then constructed by phenylselenyl-mediatcd cyclization of 14. The end game of this synthesis used the already-established cyclohexenyl zinc addition, which worked as well with 16 as it had with 7. 

An early example of the 1,2-participation-migration strategy termed the glycal assembly method was developed by Samuel Danishefsky and coworkers (Scheme 4.5a) [22], In this approach, the double bond of a glycal is converted into an epoxide or... 

The convergent approach to N-glycopeptides was first demonstrated by Peter Lansbury et al. (Scheme 11.4) [52, 53], Condensation of an oligosaccharyl amine with the Asp side chain of a suitably protected peptide was examined in solution phase but can also be carried out in solid phase. However, the drawback of this method is that the Asp unit meant to be coupled to an oligosaccharyl amine is prone to cyclic aspartimide formation with the amide nitrogen atom of the peptide backbone. Samuel Danishefsky and coworkers examined several conditions to overcome... 

A synthesis of two deoxy Lewis X pentaosyl GSLs is also reported [107]. Kyriacos Nicolaou [108], Samuel Danishefsky [109-111], and Khushi Matta [112] have reported the synthesis of the main sLex antigen. A fully automated enzymatic synthesis of sLex derivatives in 4 days and 16% overall yield from a simple GlcNac-linked aminooxy-functionalized G7 dendrimer is recently reported [113]. 

Submitted by Rajendra K. Singh and Samuel Danishefsky Checked by M. R. Czarny and M. F. Semmelhack... 

Submitted by Samuel Danishefsky, Takeshi Kitahara, and Paul F. Schuda1 Checked by Dennis Goi.ob, John Dynak, and Robert V. Stevens... 

I have had the good fortune to have many outstanding associates. Some have had, or are making, successful careers in industry, others in academia. To mention a few, in no particular order, who became professors in universities around the world Paul Wender, Paul Grieco, Samuel Danishefsky, Ian Paterson, Clayton Heathcock, Clark Still, Jacqueline Ficini, Jiro Tsuji, Minoru Isobe, Takashi Takahashi, and many more. 

The submitters would like to thank Professor Samuel J. Danishefsky and Dr, Sarah E. Danishefsky for their support and guidance. 

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