New and Stereoselective Synthesis of 1,4-Disubstituted Buten-4-ols (Homoallylic Alcohol α-Adducts) from the Corresponding γ-Isomers (3,4-Disubstituted Buten-4-ols) via an Acid-Catalyzed Allyl-Transfer Reaction with Aldehydes
作者:Shin-ichi Sumida、Masanori Ohga、Junji Mitani、Junzo Nokami
DOI:10.1021/ja990057p
日期:2000.2.1
from aldehydes via the usual reaction with common allylic metals 1, were converted to the corresponding α-adducts 6 by an acid-catalyzed allyl-transfer reaction. In the allyl-transfer reaction, anti- and syn-γ-adducts 3 gave E- and Z-α-adducts 6, respectively, and the optical purity of the γ-adducts 3 was transferred to the α-adducts 6 with >98%ee. This suggests that the allyl-transfer reaction proceeds
高烯丙基醇 3 的 γ-加合物通过与常见烯丙基金属 1 的通常反应从醛衍生,通过酸催化的烯丙基转移反应转化为相应的 α-加合物 6。在烯丙基转移反应中,反-和顺-γ-加合物3分别得到E-和Z-α-加合物6,γ-加合物3的光学纯度转移到α-加合物6,>98 %ee。这表明烯丙基转移反应通过六元环状过渡态 [T] 立体选择性地进行。该反应由各种金属三氟甲磺酸盐以及路易斯酸和布朗斯台德酸催化。