Application of stereocontrolled aldol coupling to synthesis of segments of immunosuppressants FK-506 and rapamycin
作者:James D. White、Jörg Deerberg、Steven G. Toske、Takayuki Yakura
DOI:10.1016/j.tet.2009.06.030
日期:2009.8
The sector comprising C24–C34 of FK-506 containing five of the stereogenic centers in this macrolide was synthesized from (−)-quinic acid. Aldol coupling of the C24–C34 unit with a methyl ketone representing C20–C23 of FK-506 proceeded with complete Felkin stereoselectivity to afford the C20–C34 portion of the immunosuppressant. A chelate transition state invoking coordination of a lithium enolate