Contribution of the anomeric effect to the solution and crystal structure of [1S,2S,6S,7S]-1,6-diaza-4,9-dioxa-2,7-dimethoxycarbonylbicyclo[4.4.1]undecane, a condensation product of l-serine methyl ester with formaldehyde
作者:Jimmy Sélambarom、Sophie Monge、Francis Carré、Alain Fruchier、Jean Pierre Roque、André A. Pavia
DOI:10.1016/s0008-6215(00)00261-5
日期:2001.1
7-dimethoxycarbonylbicyclo[4.4.1]undecane (4) as a 2:3 adduct of 1 with 2. 1H and 13C NMR spectroscopy were unable to discriminate between two possible symmetrical structures. The latter was unambiguously proved by X-ray crystallography. The crystalstructure established: (i) the existence of two identical seven-membered rings each containing a N-C-O grouping; (ii) the existence of a long C-O-C-N-C-N-C-O-C sequence
Conversion of isomeric 2:3 adducts (aminoacid–formaldehyde) to N-acyl-pseudoprolines derivatives
作者:Jimmy Sélambarom、Jacqueline Smadja、André A. Pavia
DOI:10.1016/j.tetlet.2004.11.134
日期:2005.1
or acid anhydrides with isomeric2:3 adducts derived from condensation of l-serine (1a), l-threonine (1b) and l-cysteine (1c) methyl esters with formaldehyde afforded N-acyl-pseudoprolines 7–19 in various yields. These 2:3 adducts can be considered as synthetic equivalents of oxaproline and thiaproline moieties. The present work revealed the versatile behaviour of the two 2:3 adducts as a consequence
A novel one-pot, two-step synthesis of N-acyl-1,3-thiazolidines and N-acyl-1,3-oxazolidines as potential double prodrugs of formaldehyde
作者:Audrey Martinez、Jimmy Sélambarom
DOI:10.1016/j.tetlet.2011.01.049
日期:2011.3
A convenient and general one-pot, two-step protocol to prepare both N-acyl-1,3-thiazolidines and N-acyl-1,3-oxazolidines from formaldehyde, fatty acyl chlorides, and natural a-amino acids has been performed for the peculiar case of formaldehyde. In the presence of triethylamine to promote both the ring-forming process and the amide bond formation, subsequent addition of the acyl donor proved to be efficient to trap the preformed stable formaldehyde-derived 1,3-thiazolidine or the transient 1,3-oxazolidine using an appropriate ratio of formaldehyde. (c) 2011 Elsevier Ltd. All rights reserved.
Stereoelectronic control of oxazolidine ring-opening: structural and chemical evidences
作者:Jimmy Sélambarom、Sophie Monge、Francis Carré、Jean Pierre Roque、André A Pavia
DOI:10.1016/s0040-4020(02)01287-5
日期:2002.11
Ringopening of oxazolidines derived from tris(hydroxymethyl)aminomethane, l-serine and l-threonine was investigated. It was shown that n(N)→σ∗(C–O) electron delocalization (endo-anomeric effect) occurring in the five-membered ring plays a major role in the cleavage of the intracyclic C–O bond. The present work establishes that when the nitrogen lone pair is conjugated with a carbonyl group (n(N)→π(CO)
Stereochemical study of 1,3-N,X-heterocycles derived from α-aminoacids and formaldehyde. Structural evidence for the existence of the anomeric effect
作者:Jimmy Sélambarom、Francis Carré、Alain Fruchier、Jean Pierre Roque、André A Pavia
DOI:10.1016/s0040-4020(02)00405-2
日期:2002.5
We have shown that condensation of l-cysteine methyl ester (8) and l-threonine methyl ester (11) with formaldehyde provides a convenient and efficient access to novel heterocyclic 2:3 adducts. Depending on the amino acid, the condensation leads to either the N,N′-methylenebis(thiazolidine) (10, l-cys) or -(oxazolidine) (13, l-thr) derivative or to its bicyclo[4.4.1]undecane isomer (5, l-ser) as the