found to react thermally with Ru3(CO)12 with fixation of the intact NN unit as a μ3-bridging ligand to the triangular metal framework. The X-ray diffraction study of the parent compound (μ2-H)Ru3(CO)9(μ3-NHNH2) (1) shows an almost undistorted hydrazido moiety coordinated as a tripodal handle to a near isosceles metal triangle.
2-Alkyl-substituted lactams 4 were synthesized in good overall yields and high enantiomeric purities (ee =71-99%) by α-alkylation of chiral N-(dialkylamino)lactams 2 and subsequent reductive N-N bond cleavage of the resulting lactams 3 with lithium in liquid ammonia. The lactams 2, in turn, were prepared in good yields by cyclization of Ï-chloroalkanohydrazides 1 with sodium hydride. Acidic hydrolysis of lactams 4 leads to γ-aminobutanoic acid (GABA) derivatives 5 (ee ≥ 99%). The absolute configuration was determined by polarimetry and an X-ray structure analysis of (S,S)-3e’.
(S)-(–)-1-Amino-2-(siloxymethyl)pyrrolidines: novel and efficient reagents for chromatographic resolution of α-substituted aldehydes
作者:Dieter Enders、Wolfgang Mies
DOI:10.1039/c39840001221
日期:——
A new aldehyderesolution technique based on the chromatographic separation (preparative h.p.l.c.) of their epimeric (S)-1-amino-2-(siloxymethyl)pyrrolidine (SASP)-hydrazones is described.