Synthesis of C 2 -symmetric tris-thioethers via optically active mustards
摘要:
Chiral dihydroxy thioethers derived from L-mandelic and L-lactic acid are activated with SOCl2, SOBr2 and by bis-trifluoroacetate formation to give optically active mustard gas analogues. These compounds serve as substrates for stereospecific nucleophilic substitution reactions with NaSEt and NaSPh to furnish C-2-symmetric tris-thioethers with overall inversion of configuration. (C) 2001 Elsevier Science Ltd. All rights reserved.
Intrinsic reactivities in the alkylations of protected amino acids by (R)- and (S)-methyloxirane
作者:Martin K. Ellis、Bernard T. Golding、William P. Watson
DOI:10.1039/p29840001737
日期:——
(5d) and its Nπ-isomer (5e) from (1b)+(5a)], a mixture [e.g.(S,S,αR/αS)-Nα-benzoyl-NπNτ-bis-(2-hydroxypropyl)-L-histidinylimidazolium carboxylates(6d)+(6e) from excess of (1b)+(5a)]. The generation of methoxide during the reactions described is responsible for the β-elimination leading to a dehydroalanine derivative and for the epimerisation during the formation of (6d)+(6e). Kinetic studies show that
Novel synthesis of chiral, enantiomerically pure thiodiglycols and diglycols
作者:Jens Christoffers、Ulrich Rößler
DOI:10.1016/s0957-4166(98)00224-9
日期:1998.7
converted in a sequence of O-protection, reduction, O-activation, thioether and ether formation and deprotection to chiral, non-racemic β,β′-dihydroxy thioethers 1a, 1b and ether 1c. Overall yields are excellent (75%). In an attempt to synthesize the respective dihydroxy ether 1d derivedfrom mandelic acid 1,3-dioxolane derivatives 7 were obtained.
Synthesis of C 2 -symmetric tris-thioethers via optically active mustards
作者:Jens Christoffers、Ulrich Rößler
DOI:10.1016/s0040-4020(01)00006-0
日期:2001.2
Chiral dihydroxy thioethers derived from L-mandelic and L-lactic acid are activated with SOCl2, SOBr2 and by bis-trifluoroacetate formation to give optically active mustard gas analogues. These compounds serve as substrates for stereospecific nucleophilic substitution reactions with NaSEt and NaSPh to furnish C-2-symmetric tris-thioethers with overall inversion of configuration. (C) 2001 Elsevier Science Ltd. All rights reserved.