1,3-二噻烷-1-N- p -chlorophenylimides(1,4 - 9)的制备和它们的配置和构象,通过测定1 H和13 C ^ NMR。将化合物重新排列为相应的2-(2'-氨基-5'-氯苯基)-1,3-二硫烷(1U,4U,9U)。重排反应以reactions95%的立体特异性发生。借助在C-2专门氘化的类似物研究了反应机理。
Addition of Lithiated 5-Hydroxymethyl-1,3-dithiane to Benzaldehyde: HMPA-Controlled Trans Stereoselectivity
作者:Zaiguo Li、Alexei N. Kurchan、Andrei G. Kutateladze
DOI:10.1021/ol0499497
日期:2004.4.1
Addition of 5-substituted dithianyl anions to carbonyl compounds normally produces trans adducts. The presence of a nucleophilic hydroxymethyl group in position 5 dramatically decreases the trans stereoselectivity of the reaction in THF. The trans/cis ratio shows a bell curve dependence on HMPA, fitted to a quantitative model involving a series of equilibrated ion pairs, of which an intermediate contact