Synthesis of threo-β-aminoalcohols from aminoaldehydes via chelation-controlled additions. Total synthesis of l-threo sphingosine and safingol
作者:Michael E. Jung、Sung Wook Yi
DOI:10.1016/j.tetlet.2012.05.153
日期:2012.8
threo-β-amino alcohol derivatives through chelation with the carbamoyl moiety. The carbamate group is a stronger chelating group than other potentially good chelators, for example ethers, esters, thioethers, and gives good diastereoselectivity with cuprates. Thus addition of lithium divinylcuprate to the aldehyde generated from the serine derivative 25 in the presence of extra copper for chelation
A Concise and Scalable Synthesis of High Enantiopurity (−)-<scp>d</scp>-<i>erythro</i>-Sphingosine Using Peptidyl Thiol Ester−Boronic Acid Cross-Coupling
作者:Hao Yang、Lanny S. Liebeskind
DOI:10.1021/ol070991m
日期:2007.8.1
A short and efficient synthesis of high enantiopurity (-)-D-erythro-sphingosine has been achieved in 71% yield over 6 steps from N-Boc-L-serine. The keysteps are high yield, racemization-free, palladium-catalyzed, copper(I)-mediated coupling of the thiophenyl ester of N-Boc-O-TBS L-serine with E-1-pentadecenyl boronic acid and the highly diastereoselective reduction of the resulting peptidyl ketone
This invention relates to a method for the production of a sphingoid base according to formula
1
comprising the steps of
(1) dissolving a starting compound according to formula III or a salt thereof in a substantially inert solvent,
2
(2) protecting the NH
2
group with a NH
2
protecting group,
(3) activating the C-4 HR
3
group for an elimination reaction with the C-5 HR
4
group,
(4) causing an elimination reaction to take place to form a double bond between the C-4 and C-5 carbon atom, and
(5) removing the NH
2
protecting group.
te lyase have been designed and tested on the bacterial (StS1PL) and the human (hS1PL) enzymes. Amino phosphates 1, 12, and 32, mimicking the intermediate aldimines of the catalytic process, were weak inhibitors on both enzyme sources. On the other hand, a series of stereodefined azido phosphates, resulting from the replacement of the amino group of the natural substrates with an azido group, afforded
Efficient stereodivergent synthesis of erythro- and threo-sphingosines: unprecedented reversal of the stereochemistry in the addition
作者:Teiichi Murakami、Kiyotaka Furusawa
DOI:10.1016/s0040-4020(02)01190-0
日期:2002.11
A convenient diastereoselective synthesis of d-erythro- and l-threo-sphingosine derivatives is described. l-Serine-derived aldehyde (Garner's aldehyde) (2) was treated with 1-alkenyl-zirconocene chlorides (3) in the presence of ZnBr2 in THF to give the natural erythro-(anti-) isomers with high diastereoselectivity (anti/syn=12–20:1). In contrast, reaction of 2 with 1-alkenyl-ethyl-zinc, prepared from
的D-阿方便非对映选择性合成赤-和1-苏式-sphingosine衍生物进行说明。L-丝氨酸衍生的醛(加纳的醛)(2)与1-链烯基锆氯化物(处理3在ZnBr的存在下)2在THF中以得到天然赤- (反- )具有高非对映选择性异构体(反/ syn = 12–20:1)。相反,2与由3和Et 2 Zn制备的1-烯基-乙基-锌在CH 2 Cl 2中的反应产生了不自然的苏氨酸-(syn-)异构体为主(anti / syn = 1:12-15)。