New Polyhydroxylated Pyrrolidines Derived from Enantiopure 3,6-Dihydro-2H-1,2-oxazines
摘要:
[GRAPHICS]Diastereoselective hydroborations of enantiopure 3,6-dihydro-2H-1,2-oxazines led to dihydroxy-substituted 1,2-oxazines. Samarium diiodide-induced N-O bond cleavage generated 1,4-amino alcohols which were recyclized to polyhydroxylated pyrrolidines which are potential glycosidase inhibitors.
New Polyhydroxylated Pyrrolidines Derived from Enantiopure 3,6-Dihydro-2H-1,2-oxazines
摘要:
[GRAPHICS]Diastereoselective hydroborations of enantiopure 3,6-dihydro-2H-1,2-oxazines led to dihydroxy-substituted 1,2-oxazines. Samarium diiodide-induced N-O bond cleavage generated 1,4-amino alcohols which were recyclized to polyhydroxylated pyrrolidines which are potential glycosidase inhibitors.
Stereodivergent Syntheses of Highly Substituted Enantiopure 4-Alkoxy-3,6-dihydro-2H-1,2-oxazines by Addition of Lithiated Alkoxyallenes to Carbohydrate-Derived Aldonitrones
Additions of lithiated alkoxyallenes to D-glyceraldehyde-based nitrones 1 and 2 did not provide the expected hydroxylamine derivatives. Instead, a novel [3+3] cyclization process furnished 4-alkoxy-3,6-dihydro-2H-1,2-oxazines 9–14 with excellent syn selectivities and in moderate to good yields. Through precomplexation of the nitrones the corresponding anti-configured 1,2-oxazines 9, 10 and 13 could
Water Freezing as a Regiocontrol Element in the Multicomponent Assembly of Cyclic Enones
作者:Raquel De la Campa、Josefa Flórez
DOI:10.1002/chem.201404670
日期:2015.1.26
Regioselective synthesis of dialkoxy 2‐cyclopentenones and 2‐cyclohexenones with novel substitution patterns has been accomplished by the one‐pot combination of three simple starting materials (chromium carbene complex, Weinreb acetamide lithium enolate and 1‐alkoxyallenyllithium) under either anhydrous conditions or water‐promoted solidification of the reaction mixture. These results revealed an unprecedented
[GRAPHICS]Diastereoselective hydroborations of enantiopure 3,6-dihydro-2H-1,2-oxazines led to dihydroxy-substituted 1,2-oxazines. Samarium diiodide-induced N-O bond cleavage generated 1,4-amino alcohols which were recyclized to polyhydroxylated pyrrolidines which are potential glycosidase inhibitors.