Design and synthesis of novel oxa-bridged isoxazolidines and 1,3-aminoalcohols

Synthesis of a Novel Taxa‐Oxa‐Sugar Hybrid Core Structure by Tandem Cross‐Enyne Metathesis/IMDA

“…The diol 28 was synthesized by the protocol developed in our laboratory [42] and was then easily converted into the aldehyde 16 by the protocol used for compound 14. Like the aldehyde 14, the aldehyde 16 was freshly prepared and used immediately for the Shapiro reaction.…”

“…Column chromatographic purification (hexanes/ethyl acetate 9.2:0. [42] (0.38 g, 1.46 mmol) in dry pyridine (3 mL), and the mixture was stirred for 2 h at 0°C and then for 12 h at room temperature. The reaction mixture was quenched with saturated NaHCO 3 (20 mL) and extracted with ethyl acetate (3 ϫ 20 mL).…”

“…Silica-supported NaIO 4 [40] was added portionwise to a stirred solution of diol 26 or 28 [42] (0.42 g, 1.61 mmol) in CH 2 Cl 2 (20 mL). The reaction mixture was stirred vigorously for 1-1.5 h and filtered, and the residue was washed with CH 2 Cl 2 (2 ϫ 20 mL).…”

Synthetic studies on taxanes: A domino-enyne metathesis/Diels-Alder approach to the AB-ring

“…The organic layer was washed (10% aqueous NH 4 Cl solution), dried (Na 2 SO 4 ), concentrated and purified by a flash column chromatography (11% EtOAc in hexanes) to afford 12 (0⋅29 g, 67% over two steps) as a white solid. 2.1d (tert-Butyl- [1-(6-methoxy-2,2-dimethyl-6-vinyltetrahydro-furo[3,4-d]dioxol-4-yl]-but-3-ynyloxy]-dimethyl-silane (13): A solution of alcohol 12 (0⋅23 g, 0⋅86 mmol) in DMF at room temperature was treated with Immidazole (0⋅175 g, 2⋅58 mmol), TBSCl (0⋅155 g, 1⋅03 mmol), catalytic amount of TBAI and then warmed to 50°C. After stirred for 24 h at 50°C, the reaction mixture was quenched with water and extracted with ethyl acetate.…”

Synthesis of alicyclic N‐substituted 1,3‐amino alcohols via 1,3‐oxazines

“…Additionally, enantiopure 1,3-amino alcohols may serve as excellent chiral auxiliaries in enantioselective transformations [5][6][7]. Although, 1,2-amino alcohols have been thoroughly investigated [8], methods for the preparation and transformation of 1,3-amino alcohols are still undergoing development [9][10][11][12][13]. Alicyclic 1,3-amino alcohols can be obtained by several methods, e.g.…”