Heteroatom Exchange
2.3
263
⊡ Scheme 76
⊡ Scheme 77
⊡ Scheme 78
are useful in Wittig alkene synthesis. A limited number of reactions of this type have been
performed on primary sugar halides. For example, the reaction of 6-iodogalactose derivative
175 with PPh 3 gives the phosphonium iodide 176 ( > Scheme 77) [121].
Other trivalent phosphorus-containing nucleophiles, such as trialkyl phosphites [P(OR 3 )],
dialkyl alkylphosphonites [R P(OR) 2 ], or alkyl dialkylphosphinites [R 2 P(OR)], can convert
primary carbohydrate halides 177, 178, 179 to corresponding phosphorus derivatives 180,
181, 182 via the Michaelis–Arbusov reaction ( > Scheme 78) [122,123].
2.3
263
⊡ Scheme 76
⊡ Scheme 77
⊡ Scheme 78
are useful in Wittig alkene synthesis. A limited number of reactions of this type have been
performed on primary sugar halides. For example, the reaction of 6-iodogalactose derivative
175 with PPh 3 gives the phosphonium iodide 176 ( > Scheme 77) [121].
Other trivalent phosphorus-containing nucleophiles, such as trialkyl phosphites [P(OR 3 )],
dialkyl alkylphosphonites [R P(OR) 2 ], or alkyl dialkylphosphinites [R 2 P(OR)], can convert
primary carbohydrate halides 177, 178, 179 to corresponding phosphorus derivatives 180,
181, 182 via the Michaelis–Arbusov reaction ( > Scheme 78) [122,123].