Access to iminosugars by aldol additions of metalated bis-lactim ethers to l-erythrose derivatives
摘要:
Aldol additions of metalated bis-lactim ethers derived from cyclo-[Gly-D-Val] 3A-E* to mismatched L-erythrose-derivatives 4a and 4b have been studied. Reactions of titanium(IV) and tin(II) azaenolates with the lactol derivative 4b allow direct and moderate (syn,syn)- or highly (anti,anti)-selective access to polyhydroxy amino acids that have been efficiently transformed into 1-deoxy-D-gulonojirimycin or 1-deoxy-D-allonojirimycin. (C) 2002 Elsevier Science Ltd. All rights reserved.
Access to iminosugars by aldol additions of metalated bis-lactim ethers to l-erythrose derivatives
摘要:
Aldol additions of metalated bis-lactim ethers derived from cyclo-[Gly-D-Val] 3A-E* to mismatched L-erythrose-derivatives 4a and 4b have been studied. Reactions of titanium(IV) and tin(II) azaenolates with the lactol derivative 4b allow direct and moderate (syn,syn)- or highly (anti,anti)-selective access to polyhydroxy amino acids that have been efficiently transformed into 1-deoxy-D-gulonojirimycin or 1-deoxy-D-allonojirimycin. (C) 2002 Elsevier Science Ltd. All rights reserved.
Diastereoselective Synthesis of Piperidine Imino Sugars Using Aldol Additions of Metalated Bislactim Ethers to Threose and Erythrose Acetonides
作者:María Ruiz、Tania M. Ruanova、Olga Blanco、Fátima Núñez、Cristina Pato、Vicente Ojea
DOI:10.1021/jo702601z
日期:2008.3.1
anti-selectivity for the mismatched ones may originate from (1) the intervention of solvated aggregates of tin(II) azaenolate and lithium chloride as the reactive species and (2) favored chair-like transition structures with a Cornforth-like conformation for the aldehyde moiety. DFT calculations indicate that aldol additions to erythrose acetonides proceed by an initial deprotonation, followed by coordination
Access to iminosugars by aldol additions of metalated bis-lactim ethers to l-erythrose derivatives
作者:Marı́a Ruiz、Vicente Ojea、Tania M. Ruanova、José M. Quintela
DOI:10.1016/s0957-4166(02)00189-1
日期:2002.5
Aldol additions of metalated bis-lactim ethers derived from cyclo-[Gly-D-Val] 3A-E* to mismatched L-erythrose-derivatives 4a and 4b have been studied. Reactions of titanium(IV) and tin(II) azaenolates with the lactol derivative 4b allow direct and moderate (syn,syn)- or highly (anti,anti)-selective access to polyhydroxy amino acids that have been efficiently transformed into 1-deoxy-D-gulonojirimycin or 1-deoxy-D-allonojirimycin. (C) 2002 Elsevier Science Ltd. All rights reserved.