Regio- and stereo-selective synthesis of carbohydrate isoxazolidines by 1,3-dipolar cycloaddition of nitrones to 5,6-dideoxy-1,2-O-isopropylidene-α-D-xylo-hex-5-enofuranose

Article abstract of DOI:10.1016/0008-6215(92)84054-V

The synthesis of 2-phenyl-3-aryl and 2-phenyl-3-aroyl derivatives 5-(1,2-O-isopropylidene-α-D-xylo-tetrofuranos-4-yl)isoxazolidine (3) from nitrones and 5,6-dideoxy-1,2-O-isopropylidene-α-D-xylo-hex-5-enofuranose (1) is described. The 1,3-dipolar cycloaddition reactions give mainly anti adducts 3 and 4 (≥ 95% π-facial stereoselectivity). The cycloadducts 3 with H-3,5 cis are formed either exclusively or preponderate over the trans diastereoisomers 4. The synthesis of 2-phenyl-3-aryl and 2-phenyl-3-aroyl derivatives 5-(1,2-O-isopropylidene-α-D-xylo-tetrofuranos-4-yl)isoxazolidin e (3) from nitrones and 5,6-dideoxy-1,2-O-isopropylidene-α-D-xylo-hex-5-enofuranose (1) is described. The 1,3-dipolar cycloaddition reactions give mainly anti adducts 3 and 4 (≥ 95% π-facial stereoselectivity). The cycloadducts 3 with H-3,5 cis are formed either exclusively or preponderate over the trans diastereoisomers 4.