184840-85-5Relevant academic research and scientific papers
Asymmetric syntheses of methyl N-Boc-2-deoxy-2-amino-l-erythroside, methyl N-Boc-2-deoxy-2-amino-d-threoside and methyl N-Boc-2,3-dideoxy-3-amino-l- arabinopyranoside
Brambilla, Marta,Davies, Stephen G.,Fletcher, Ai M.,Hao, Li,Lv, Linlu,Roberts, Paul M.,Thomson, James E.
, p. 3491 - 3501 (2014/05/06)
The asymmetric syntheses of methyl N-Boc-2-deoxy-2-amino-l-erythroside and methyl N-Boc-2-deoxy-2-amino-d-threoside have been achieved from sorbic acid, in six and eight steps, and in 35 and 13% overall yield, respectively. Diastereoselective aminohydroxy
Highly diastereoselective and stereodivergent dihydroxylations of acyclic allylic amines: Application to the asymmetric synthesis of 3,6-dideoxy-3-amino- l-talose
Csatayova, Kristina,Davies, Stephen G.,Lee, James A.,Roberts, Paul M.,Russell, Angela J.,Thomson, James E.,Wilson, David L.
supporting information; experimental part, p. 2606 - 2609 (2011/07/08)
Aminohydroxylation of tert-butyl sorbate [tert-butyl (E,E)-hexa-2,4- dienoate] using enantiopure lithium (R)-N-benzyl-N-(α-methylbenzyl)amide and (-)-camphorsulfonyloxaziridine gives tert-butyl (R,R,R,E)-2-hydroxy-3-[N- benzyl-N-(α-methylbenzyl)amino]hex-4-enoate in >99:1 dr. Subsequent dihydroxylation under Upjohn conditions (OsO4/NMO) gives tert-butyl (2R,3R,4S,5S,αR)-2,4,5-trihydroxy-3-[N-benzyl-N-(α-methylbenzyl) amino]hexanoate (in 95:5 dr) while dihydroxylation under Donohoe conditions (OsO4/TMEDA) proceeds with antipodal diastereofacial selectivity to give the (R,R,R,R,R)-diastereoisomer (in 95:5 dr). The amino triols resulting from these dihydroxylation reactions are useful for further elaboration, as demonstrated by the asymmetric synthesis of 3,6-dideoxy-3-amino-l-talose.
Concise and highly selective asymmetric synthesis of acosamine from sorbic acid
Bagal, Sharan K.,Davies, Stephen G.,Fletcher, Ai M.,Lee, James A.,Roberts, Paul M.,Scott, Philip M.,Thomson, James E.
scheme or table, p. 2216 - 2220 (2011/05/09)
Diastereoselective conjugate addition of lithium (R)-N-benzyl-N-(α- methylbenzyl)amide to tert-butyl sorbate and subsequent chemo- and diastereoselective ammonium-directed olefinic oxidation of the resultant conjugate addition product {tert-butyl (3S,αR)-3-[N-benzyl-N-(α- methylbenzyl)amino]hex-4-ene} have been used as the key steps in a concise and highly selective asymmetric synthesis of the 2,3,6-trideoxy-3-aminohexose l-acosamine. This sequence of two chemical operations allows rapid assembly of the molecular architecture and facilitates the de novo asymmetric synthesis of methyl N,O-diacetyl-α-l-acosaminide in only 7 steps from commercially available sorbic acid in 15% overall yield.
Asymmetric synthesis of (R)-hexane-1,5-diol, (R)-hex-3-ene-1,5-diol and (R)-6-methylhept-5-en-2-ol (sulcatol) employing a tandem asymmetric conjugate addition and stereospecific Meisenheimer rearrangement protocol
Davies, Stephen G.,Smyth, G. Darren
, p. 2467 - 2477 (2007/10/03)
Highly stereoselective conjugate addition of lithium (R)-N-methyl-(α-methylbenzyl)amide to tert-butyl (E,E)-hexa-2,4-dienoate, followed by reduction of the ester to the corresponding alcohol, affords a substrate which undergoes, upon oxidation, a stereospecific Meisenheimer rearrangement to give a single diastereomer of the corresponding trialkylhydroxylamine. The analogous N-benzyl adduct gives lower yields in the oxidation-rearrangement reaction. If the ester is not reduced to the alcohol, N-oxidation leads to Cope elimination, not Meisenheimer rearrangement. Cleavage of the N-O bond gives (R)-hex-3-ene-1,5-diol, and hydrogenation of the double bond affords (R)-hexane-1,5-diol in high ee. This methodology has been applied to the synthesis of the insect pheromone (R)-6-methylhept-5-en-2-ol (sulcatol) from tert-butyl (E,E)-hexa-2,4-dienoate, via a sequence involving conjugate addition of the lithium amide, Grignard addition to the ester, Meisenheimer rearrangement, hydrogenation of the double bond, dehydration of the tertiary alcohol and finally N-O bond cleavage.
