in the presence of SnCl4 underwent an intramolecular rearrangement to give 2,5-anhydro ester 7. On the other hand the lyxo epimeric epoxide 5 under the same conditions afforded esters 7 and 8. Ester 7 was transformed into racemic epiallomuscarine (12), whereas the isomer 8 into racemic epimuscarine (13).
丁基2-O-乙酰基-4,5-脱
水-3,6-二脱氧DL-
低聚木糖-hexaldonate(4)中的SnCl存在4行的分子内重排以得到2,5-脱
水酯7.在其他在相同条件下,将lyxo差向异构环氧化合物5得到酯7和8。酯7被转化为外消旋表alcaruscarine(12),而异构体8被转化为外消旋epimuscarine(13)。