2,3-Dihydro-4-pyranones were synthesized stereoselectively using a chiral phosphine oxide as the catalyst. The phosphine oxide sequentially activated silicon tetrachloride and promoted the double aldol reaction of 4-methoxy-3-buten-2-one with aldehydes. Subsequent stereoselective cyclization afforded the corresponding highly functionalized 2,3-dihydro-4-pyranones bearing three contiguous chiral centers in good yields and with high diastereo- and enantioselectivities.
2,3-二氢-4-
吡喃酮是使用手性氧化膦作为催化剂,通过立体选择性方法合成的。氧化膦依次活化了
四氯化硅,并促进了
4-甲氧基-3-丁烯-2-酮与醛的双
缩醛反应。随后的立体选择性环化反应产生了相应的具有三个连续手性中心的2,3-二氢-4-
吡喃酮,收率良好,且具有高立体异构选择性。