کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5215325 | 1383225 | 2015 | 6 صفحه PDF | دانلود رایگان |
Two results are described. First, quinic acid was transformed into the monoacetate of 2-cyclohexene-1,4-diol. The Ni-catalyzed allylic substitution of the monoacetate with CH2C(Me)MgBr/ZnCl2/TMEDA followed by oxidation of the resulting SN2-type product afforded the 4-(CH2C(Me))-substituted 2-cyclohexenone. BF3·OEt2-assisted 1,4-addition of the enone with (4-MeOC6H4)2Cu(MgBr)·MgBr2 furnished the ketone, which is the key intermediate for the synthesis of cyclobakuchiols A and C. Second, the allylic picolinate with CMe2(OTES) and 4-MeOC6H4 groups at 3 and 4 positions of the cyclohexane ring was synthesized through 1,4-addition of (4-MeOC6H4)2Cu(MgBr)·MgBr2 to 4-(CMe2(OTES))-2-cyclohexenone. Allylic substitution of this picolinate followed by deprotection furnished cyclobakuchiol C. Furthermore, the methyl ether of cyclobakuchiol C was transformed to cyclobakuchiol A.
Journal: Tetrahedron - Volume 71, Issue 16, 22 April 2015, Pages 2387-2392