LiNH2BH3-promoted reductive opening of 8-substituted phenylglycinol-derived oxazolopiperidone lactams leads to enantiopure 4-substituted-5-aminopentanols, which are used as starting building blocks in the synthesis of the Haliclona alkaloids haliclorensin C, haliclorensin, and halitulin (formal). The starting lactams are easily accessible by a cyclocondensation reaction of (R)-phenylglycinol with racemic γ-subtituted
A General Method for the Synthesis of Enantiopure 1,5-Amino Alcohols
作者:Guillaume Guignard、Núria Llor、Aina Urbina、Joan Bosch、Mercedes Amat
DOI:10.1002/ejoc.201501409
日期:2016.2
(R)-phenylglycinol-derived oxazolopiperidone lactams 1–14 were converted to linear-chain enantiopure amino diols 15–26 by reduction with LiNH2BH3 in an unprecedented process involving the simultaneous reductive opening of the oxazolidine and lactam rings. Subsequent removal of the phenylethanol moiety gave enantiopure 5-amino-1-pentanols bearing substituents at the 2-, 3-, 4-, 2,2-, 2,3- 2,4- and 3,4-positions
Derivatives of pyrazolopyrimidine compounds represented by Formula I are disclosed:
These pyrazolopyrimidine derivatives and pharmaceutical compositions comprising these derivatives are useful in the treatment of HIV mediated diseases and conditions.
Regioselective Endocyclic Oxidation of Enantiopure 3‐Alkylpiperidines: Synthesis of (3<i>S</i>,5<i>S</i>)‐(‐)‐3‐Ethyl‐5‐Methylpiperidine
作者:Alejandro Castro、Jorge Juárez、Dino Gnecco、Joel L. Terán、Laura Orea,、Sylvain Bernès
DOI:10.1080/00397910500466454
日期:2006.3.1
An efficient regioselective endocyclic oxidation of enantiopure 3-alkylpiperidines 1( a-c) with bromine in acetic acid to generate the corresponding 5-alkylpiperidin-2-ones 3(a-c) as main product is described. In addition, starting from 3a or 3b, the synthesis of (3S,5S)-(-)-3-ethyl-5-methylpiperidine 6 (.) HCl was achieved. Finally, the X-ray single-crystal analysis of compound 4 is reported.
Diastereoselective Synthesis of 3-Alkylindoloquinolizine Derivatives via Regiospecific Oxidative Cyclization
作者:Jorge R. Juárez、Susana Morales-Barba、Joel L. Terán、Dino Gnecco、María L. Orea、David M. Aparicio、Víctor Gómez-Calvario
DOI:10.3987/com-19-14058
日期:——
3-Alkylindoloquinolizine alkaloids were synthetized in two steps from enantiopure 3-alkylpiperidines through sequential N-alkylation and regiospecific and diastereoselective oxidative cyclization. INTRODUCTION The indoloquinolizine framework is widely distributed in both pharmaceuticals and natural products (e.g. Figure 1) showing a wide range of pharmacological activities such as analgesic,1 anti-inflammatory