ChemInform Abstract: Concise General Synthesis of α,γ‐Disubstituted β‐ Amino Ketones from β‐Lactams.

Abstract

1995 ketones ketones (acyclic compounds) P 0200 -089Concise General Synthesis of α,γ-Disubstituted β-Amino Ketones from β-Lactams.-Ring opening of 3,4-disubstituted N-Boc-β-lactams such as (I), promoted by aryl-Grignard reagents, yields the α,γ-disubstituted β-amino ketones (III). The same reaction starting at -78 • C and warming to room temp. leads to the corresponding carbinols of type (VI)/(IX). These are obtained in a mixture with (V) by use of primary alkylmagnesium halides in the reaction with (I), where chlorides increase the amount of β-amino ketones. The method is extended to the preparation of differently functionalized analogues and proved to represent a general access to products which may be employed as precursors of α-amino acids and polyhydroxylated nitrogen-containing compounds. -(PALOMO, C.; AIZPURUA, J. M.; GARCIA, J. M.; ITURBURU, M.; ODRIOZOLA, J. M.; J.

Stereoselective Synthesis of Highly Functionalized 5- and 6-Membered Aminocyclitols Starting with a Readily Available 2-Azetidinone

“…1H),1H),1H),4.95 (d,J = 9.6 Hz,1H),4.61 (d,J = 11.7 Hz,1H),1H),4.39 (d,J = 11.7 Hz, 1H), 3.92 (t, J = 3.5 Hz, 1H), 2.07 (s, 3H); 13 C{ 1 H} NMR (125 MHz, CDCl 3 ) δ 170. 1, 150.0, 146.5, 137.1, 133.4, 132.3, 128.5, 128.3, 128.1, 127.5, 124.3, 89.6, 81.1, 72.1, 63.2 (1S,2R,4R,5R,6R)-5-(Benzyloxy)-6-((tert-butoxycarbonyl)amino)cyclohexane-1,2,4-triyl triacetate (17). To an ice-cold solution of 11 (30 mg, 0.09 mmol) in acetone/water 9:1, NMO (22 mg, 0.19 mmol) was added followed by an OsO 4 (0.6 mg, 2.5 mol %) solution in tBuOH, and the reaction was stirred at room temperature for 8 h. After completion of the reaction, it was quenched by the addition of Na 2 S 2 O 3 and the acetone was evaporated under reduced pressure.…”