168777-85-3Relevant academic research and scientific papers
Total Synthesis of Rapamycin
Nicolaou, K. C.,Piscopio, Anthony D.,Bertinato, Peter,Chakraborty, Tushar K.,Minowa, Nobuto,Koide, Kazunori
, p. 318 - 333 (2007/10/02)
Details of the total synthesis of rapamycin (1) are reported.The synthesis required the preparation of intermediates 4-9 in nonracemic form; key coupling reactions included a chromium-mediated addition of vinyl iodide 8 to aldehyde 7 and an Evans aldol reaction to couple fragments 62 and 9.Intermediates 4 and 6 were joined through an amide bond formation to afford advanced intermediate 71.Swern oxidation of the diol in 71 was followed by a selective removal of the TES groups and a second Swern oxidation.Finally, removal of the remaining silyl protecting groups provided fully deprotected, penultimate intermediate 2 in which all carbons were in their proper oxidation state.Macrocyclization was achived through a tandem inter/intramolecular palladium-mediated Stille coupling reaction between distannylethene 3 and bis(vinyl iodide) 2.This latter process accomplished in one step the installation of the remaining two carbons of the natural product and the completion of its total synthesis. - Keywords: rapamycin, stannylethenes, Stille coupling, vinyl iodides
