One-Pot Preparation of Quinolizidin-2-one and Indolizidin-7-one Ring Systems. Concise Total Syntheses of (.+-.)-Myrtine, (.+-.)-Lasubine II, and (-)-Indolizidine 223AB
作者:Ronaldo A. Pilli、Luiz Carlos Dias、Adriano O. Maldaner
DOI:10.1021/jo00108a040
日期:1995.2
highly efficient approach to the quinolizidine alkaloids (+/-)-myrtine (4) and (+/-)-lasubine II (5) and to the indolizidine alkaloid (-)-indolizidine 223AB (6) is described. The preparation of quinolizidin-2-ones 4/4a and 11b/12b and indolizidin-7-ones 16/17 is based on the addition of 2-((trimethylsilyl)oxy) 1,3-dienes 2a,b and 2c to cyclic N-acyliminium ions 10 and 15, respectively. It encompasses five chemical transformations in the same pot yielding the axially oriented substituent at C-4 and C-5 as the major product in the quinolizidin-2-one and indolizidin-7-one systems, respectively. The thermodynamically more stable isomers 12b and 17 were obtained after basic treatment.
Asymmetric synthesis of 3,5-disubstituted indolizidines by intermolecular addition of an allylsilane on an N-acyliminium ion
A diastereoselective synthesis of 3,5-disubstituted indolizidines based on an intermolecular addition of an allylsilane on an acyliminium ion derived from (S)-pyroglutamic acid is described. The synthetic potential of this methodology is demonstrated by the enantioselective synthesis of (-)-indolizidine 195B, (-)-indolizidine 223AB, (+)-monomorine and (-)-3-butyl-5-propyl indolizidine. (c) 2006 Elsevier Ltd. All rights reserved.
Highly Diastereoselective and Enantioselective Preparation of Homoallylic Amines: Application for the Synthesis of β-Amino Acids and γ-Lactams
作者:P. Veeraraghavan Ramachandran、Thomas E. Burghardt
DOI:10.1002/chem.200401295
日期:2005.7.18
furnished homoallylic amines in good yields and high ee. A 11B NMR spectroscopy study revealed that the reactions do not proceed, even at room temperature, unless a molar equivalent of water or methanol is added. The first reagent-controlled asymmetric crotylboration and alkoxyallylboration of aldimines furnishing beta-methyl or beta-alkoxy homoallylic amines in very high diastereoselectivity and enantioselectivity
Total synthesis of (+) monomorine I from chiral cyclic β-enamino ester
作者:C. Saliou、A. Fleurant、J.P. Célérier、G. Lhommet
DOI:10.1016/s0040-4039(00)92707-2
日期:1991.7
We describe the total synthesis of (+) Monormorine I 1 and the preparation of cis 2,5 disubstituted functionalized pyrrolidines via cyclic β-enamino esters 4, starting from (S)-pyroglutamic acid.
我们描述了(+)Monormorine I 1的总合成,以及从(S)-焦谷氨酸开始通过环状β-烯胺酯4制备顺式2,5双取代的官能化吡咯烷。