A facile synthesis of chiral ω-allyl- and ω-n-propyllactones via asymmetric allylboration of formyl esters with B-allyldiisopinocampheylborane
摘要:
Asymmetric allylboration of aldehydes containing an adjacent ester group with B-allyldiisopinocampheylborane, followed by hydrolysis and cyclization, provides the corresponding allyl substituted lactones in high yields and greater than or equal to 92% enantiomeric excess. Hydrogenation of these lactones provides the corresponding propyl substituted lactones without any loss of optical purity. (C) 1999 Elsevier Science Ltd. All rights reserved.
A facile synthesis of chiral ω-allyl- and ω-n-propyllactones via asymmetric allylboration of formyl esters with B-allyldiisopinocampheylborane
摘要:
Asymmetric allylboration of aldehydes containing an adjacent ester group with B-allyldiisopinocampheylborane, followed by hydrolysis and cyclization, provides the corresponding allyl substituted lactones in high yields and greater than or equal to 92% enantiomeric excess. Hydrogenation of these lactones provides the corresponding propyl substituted lactones without any loss of optical purity. (C) 1999 Elsevier Science Ltd. All rights reserved.
A rapid convergentstrategy to access unsaturated analogues of peloruside A has been demonstrated. This is depicted as an original C11-C12 aldol connection between a C12-C20 ketone fragment and a C2-C11 pyran fragment bearing an aldehyde function, with high yield and a good level of diastereoselectivity. The desired unsaturated macrocycle was obtained by a late-stage ring closing metathesis reaction
已经证明了一种获取 peloruside A 的不饱和类似物的快速收敛策略。这被描述为 C12-C20 酮片段和带有醛官能团的 C2-C11 吡喃片段之间的原始 C11-C12 醛醇连接,具有高产率和良好的非对映选择性。通过后期闭环复分解反应获得所需的不饱和大环。
Stereoselective allylation of aldehydes on solid support and its application in biology-oriented synthesis (BIOS)
作者:Victor Mamane、Ana B. García、Jayant D. Umarye、Torben Lessmann、Stefan Sommer、Herbert Waldmann
DOI:10.1016/j.tet.2007.01.041
日期:2007.6
allylation of aldehydes on solid support is reported. Different kinds of chiral allylboron reagents with complementary direction of stereoinduction were applied successfully in this reagent-controlled transformation. The homoallylic alcohol products are generated with high levels of stereoselectivity and in high yields. The crotylation of aldehydes on solid support employing (E)- and (Z)-Ipc2crotylborane
A facile synthesis of chiral ω-allyl- and ω-n-propyllactones via asymmetric allylboration of formyl esters with B-allyldiisopinocampheylborane
作者:P.Veeraraghavan Ramachandran、Marek P. Krzeminski、M.Venkat Ram Reddy†、Herbert C. Brown
DOI:10.1016/s0957-4166(98)00477-7
日期:1999.1
Asymmetric allylboration of aldehydes containing an adjacent ester group with B-allyldiisopinocampheylborane, followed by hydrolysis and cyclization, provides the corresponding allyl substituted lactones in high yields and greater than or equal to 92% enantiomeric excess. Hydrogenation of these lactones provides the corresponding propyl substituted lactones without any loss of optical purity. (C) 1999 Elsevier Science Ltd. All rights reserved.