Zobrazeno 1 - 10
of 52
pro vyhledávání: '"Robert Lett"'
Publikováno v:
Synlett. 26:1340-1344
The nonreductive cleavage of a model 3,6-dihydro-1,2-oxazine by condensation of 2,2-dimethoxyacetaldehyde under aqueous conditions is investigated. Depending on the pH of the solution, the reaction leads either to the N-acylated 1,4-amino alcohol or
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::0c3bef927a671c1a5a194f22ea5c2625
https://doi.org/10.1055/s-0034-1380533
https://doi.org/10.1055/s-0034-1380533
Publikováno v:
Chemistry - A European Journal. 19:15604-15614
The regioselectivity of the nitroso-Diels-Alder reaction between unsymmetrical acyclic dienes and Boc-nitroso (Boc=tert-butoxycarbonyl) reagent or the Wightman chiral chloronitroso reagents has been studied. With the Boc-nitroso reagent, the selectiv
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::51c5922a7a018b5026cc31d84ca97e87
https://doi.org/10.1002/chem.201302905
https://doi.org/10.1002/chem.201302905
Autor:
Marc Port, Robert Lett
Publikováno v:
Tetrahedron Letters. 47:4671-4675
19-Nor steroids and RU486 tricyclic synthetic intermediates were stereoselectively prepared by an intramolecular Diels–Alder reaction involving an o -quinodimethane possessing a pro -17 unique chiral stereocenter, substituted by a protected hydroxy
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::62777e84a30f40de0863e3f7c111c99e
https://doi.org/10.1016/j.tetlet.2006.04.129
https://doi.org/10.1016/j.tetlet.2006.04.129
Autor:
Marc Port, Robert Lett
Publikováno v:
Tetrahedron Letters. 47:4677-4681
In a synthetic approach to 19-nor steroids and in order to compare the diastereoselectivities observed for the intramolecular Diels–Alder reactions of o -quinodimethanes generated either from 1 or 2 , the thermolysis of benzocyclobutenes such as 2
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::6d486b999b2b88b0f3fe7265694d5650
https://doi.org/10.1016/j.tetlet.2006.04.128
https://doi.org/10.1016/j.tetlet.2006.04.128
Autor:
Nicolas Zorn, Robert Lett
Publikováno v:
Tetrahedron Letters. 47:4325-4330
The stereospecific synthesis of the dienophile subunits 5 was achieved from the butenolide 6. Ester 19 was obtained in 67% overall yield (2 steps), with no intermediate purification, by a sodium chlorite oxidation of the corresponding aldehyde in buf
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::6b4bd0482533a26cbccb0419d0fee805
https://doi.org/10.1016/j.tetlet.2006.04.113
https://doi.org/10.1016/j.tetlet.2006.04.113
Autor:
Nicolas Zorn, Robert Lett
Publikováno v:
Tetrahedron Letters. 47:4331-4335
A highly selective synthesis of the enol triflate derived from the 9-keto group was achieved directly from the Wieland–Miescher ketone or an analog in kinetic conditions with LHMDS/THF–HMPA and Comins reagent. The other isomeric triflates were al
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::1e66fb4d4d136b3f339396a6d2162da4
https://doi.org/10.1016/j.tetlet.2006.03.185
https://doi.org/10.1016/j.tetlet.2006.03.185
Autor:
Emmanuelle Queron, Robert Lett
Publikováno v:
Tetrahedron Letters. 45:4539-4543
The 16-membered macrolide formation of a bafilomycin A 1 synthesis intermediate showed to be very difficult to achieve via an intramolecular Stille reaction. Complex reactions were observed, depending on the nature of the palladium source, ligand, so
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::c400458a4e655721bb8b61e56d95a4f0
https://doi.org/10.1016/j.tetlet.2004.04.035
https://doi.org/10.1016/j.tetlet.2004.04.035
Autor:
Emmanuelle Queron, Robert Lett
Publikováno v:
Tetrahedron Letters. 45:4527-4531
The synthesis of the enantiopure C 1 –C 11 fragment of bafilomycin A 1 has been achieved with a 4% overall yield over 18 steps from ( R )-(+)-citronellol. Key steps involve Sharpless asymmetric epoxidation, Miyashita reaction of a γ,δ-epoxymethac
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::9a84aaffc33cdb43ffbbb8a96f29f6f7
https://doi.org/10.1016/j.tetlet.2004.04.033
https://doi.org/10.1016/j.tetlet.2004.04.033
Autor:
Robert Lett, Emmanuelle Queron
Publikováno v:
Tetrahedron Letters. 45:4533-4537
Stereoselective addition of ( E )-1-lithio-2-tributylstannylethylene on a chiral cyclic di- t -butylsilyleneketal C 14 –C 17 aldehyde afforded the required Felkin–Anh adduct for the synthesis of the C 12 –C 17 fragment of bafilomycin A 1 , the
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::82c7b78eca8e7a555f5fb55bb2521d2c
https://doi.org/10.1016/j.tetlet.2004.04.034
https://doi.org/10.1016/j.tetlet.2004.04.034
Autor:
Patrice Selles, Robert Lett
Publikováno v:
Tetrahedron Letters. 43:4621-4625
The stereospecific synthesis of the precursors required for the 14-membered ring formation either via an intramolecular Suzuki coupling or via an intermolecular Suzuki coupling followed by a macrolactonisation is herein reported. One-pot Suzuki coupl
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::0e585db071403168b578b07a29fded66
https://doi.org/10.1016/s0040-4039(02)00870-5
https://doi.org/10.1016/s0040-4039(02)00870-5