Highly regio- and stereoselective cyclic iodoetherification of 4,5-alkadienols. An efficient preparation of 2-(1'(Z)-iodoalkenyl)tetrahydrofurans.
In this paper, an efficient way to synthesize 2-(1'(Z)-iodoalkenyl)tetrahydrofurans from 4,5-alkadienols and I(2) was developed. The reaction of the 4,5-allenols with a substituent in the 3-position afforded the trans-2,3-disubstituted tetrahydrofurans with very high diastereoselectivity. However, when the axially optically active 4,5-allenol was treated with I(2) in n-hexane, the efficiency for chirality transfer was low. This problem was circumvented by conducting the reaction in CH(2)Cl(2) at room temperature and applying N-iodosuccinimide as the electrophilic reagent; however, the Z/E ratio for the products is much lower. Highly optically active Z-products may be prepared via the kinetic resolution via a Sonogashira coupling reaction with propargyl alcohol.
Lü
Bo
B
Laboratory of Molecular Recognition and Synthesis, Department of Chemistry, Zhejiang University, Hangzhou 310027, Zhejiang, People's Republic of China.
Jiang
Xinpeng
X
Fu
Chunling
C
Ma
Shengming
S
D000438:Alcohols / Q000737:chemistry*; D003500:Cyclization; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry; D007455:Iodine / Q000737:chemistry; D008968:Molecular Conformation; D013237:Stereoisomerism
D000438:Alcohols; D005663:Furans; D007455:Iodine