固相β-环糊精包结物诱导7-羟基-2-甲氧基-2-甲基色满的不对称合成

研究了室温下间苯二酚和甲基乙烯基酮分别与β-环糊精（ β-CD）形成包结物后的几种不同固相反应，结果表明包结物A（间苯二酚/β-CD）与包结物B（甲基乙烯基酮/β-CD）反应能够很好地得到目的产物，产率及ee值分别为82.8%和78.4%；间苯二酚与包结物B反应仅得到低光学活性产物（ee值为19.5%）；包结物A与甲基乙烯基酮反应却没有得到手性目的产物。以熔点、X-粉末衍射、固相核磁碳谱及ROESY多种方法对所形成的包结物进行了表征，包结物中主客体的比例（1：1）通过¹H NMR (400 MHz)得以确定，文章对固相环加成反应的机制也进行了初步探讨。

Asymmetric Synthesis of 2‐Methoxy‐2‐methylchroman‐7‐ol in Solid‐state β ‐Cyclodextrin Complexes

A chiral product, (+)‐2‐methoxy‐2‐methylchroman‐7‐ol, was obtained from β‐cyclodextrin (β‐CD)/1,3‐dihydroxylbenzene (complex A ) and methyl vinyl ketone/β‐cyclodextrin (complex B ). The reaction was carried out at room temperature in a solid state to give the desired product in 82.8% yield and 78.4% ee. Low optically active product (19.5% ee) was obtained from complex B and 1,3‐dihydroxylbenzene ( A ), and non‐optically active product was obtained from complex A and methyl vinyl ketone ( B ) under the same conditions. The structures of the inclusion compounds were elucidated by melting points, X‐ray diffraction, solid‐state ¹³C CP/MAS NMR (100 MHz, spin?5000), and ROESY analyses. The ratios (1:1) of host‐guest in the inclusion compounds were decided by ¹H NMR spectra (400 MHz). The mechanism of the solid‐state conjugated cyclic addition reaction was also discussed.