Homochirale 2, 4??disubstituierte 1, 3??Dioxane aus (S)??(−)??Äpfelsäure: Stereoselektive Synthese und Untersuchung der NMDA??Rezeptoraffinität aller vier …
B Wünsch, H Diekmann…
文献索引：Wuensch, Bernhard; Diekmann, Heike; Hoefner, Georg Liebigs Annalen der Chemie, 1993 , # 12 p. 1273 - 1278
(R, S)-16 are prepared: Transacetalisation of benzaldehyde dimethyl acetal (6b) with (S)-(-)- methyl 2, 4-dihydroxybutyrate (? a), which is obtained by chemoselective BH3 reduction of (5')-(-)-malic acid monoester 8b, yields the diastereomeric 1, 3-dioxane derivatives (S, S)-10 and (R, S)-11 in a 85: 15 ratio. LDA deprotonation of (S, S)-10 followed by protonation leads to C-4 epimerisation [(S, S)-lO:(S, R)-11= 30:? 0]. The thermodynamically controlled 88: 12 ...
