Reinvestigation of palladium-catalyzed allylation of the monoacetate of 4-cyclopentene-1,3-diol and synthesis of the coronafacic acid ethyl ester
作者:Wataru Kinouchi、Yusuke Kosaki、Yuichi Kobayashi
DOI:10.1016/j.tetlet.2013.10.052
日期:2013.12
A larger quantity of a β-keto ester that is 1.5–1.7 equiv more than the base (t-BuOK, NaH) was found to be essential in securing sufficient yields of the products in the palladium-catalyzed allylic substitution of the monoacetate of 4-cyclopentene-1,3-diol with β-keto esters. This requirement also works well for substitutions with the TBS ether of the monoacetate and the monoacetate of 2-cyclohexene-1
Diastereoselective Preparation of Substituted δ-Valerolactones. Synthesis of (3<i>R</i>,4<i>S</i>)- and (3<i>R</i>,4<i>R</i>)-Simplactones
作者:Antonio Osorio-Lozada、Horacio F. Olivo
DOI:10.1021/jo8025548
日期:2009.2.6
were achieved in 5 steps from N-acyl thiazolidinethione chiral auxiliaries. The syntheses feature a double diastereoselective acetate aldol reaction solely controlled by the chirality of the auxiliary. Highly diastereoselective aldol reactions with s-trioxane were also achieved with N-acyl thiazolidinethione auxiliaries and the stereochemistry of an aldol product confirmed by X-ray analysis.