ISSN:
0947-6539
Keywords:
asymmetric synthesis
;
dioxiranes
;
ruthenium
;
sulforaphane
;
sulfoxides
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
A new enantioselective (80% ee) synthesis of (R)-sulforaphane and its epimer (S)-sulforaphane is described, which makes use of the pseudo-tetrahedral complex fragment [CpRu-(CHIRAPHOS)]+ as a chiral auxiliary. Reaction of the chloride complexes [CpRu(L-L)Cl] [L-L = 1,-bis(diphenylphosphino)ethane (dppe), (2S,3S)-and (2R,3R)-bis(diphenylphosphino)-butane ((S,S)- and (R, R)-CHIRAPHOS, respectively)] with phthalimidobutyl methyl sulfide gives the thioether complexes [CpRu(L-L)(MeSC4H8NPhth)]PF6. Oxygen transfer from dimethyldioxirane (DMD) produces the corresponding sulfoxide complexes in high yield and high diastereoselectivity. Cleavage of the phthaloyl group with aqueous hydrazine and subsequent reaction with thiophosgene yields the sulforaphane complexes [CpRu(L-L)(MeS(O)C4H8NCS)]PF6. Treatment of these with sodium iodide finally liberates the sulforaphane without noticeable racemization.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/chem.19970030510
