The Diastereoselective Formation of 1,2,4-Trioxanes and 1,3-Dioxolanes by the reaction of endoperoxides with chiral cyclohexanones
作者:Charles W. Jefford、Shu-Juan Jin、G�rald Bernardinelli
DOI:10.1002/hlca.19970800813
日期:1997.12.15
4-dipheny 1-2,3-dioxabicyclo[2.2.2]oct-5-ene (32) with 10 and 1.1 equiv. of Me3SiOTf produces only the pair of trioxanes 33 and 34 homologous to 11 and 12. Treatment of the (S,S)-diastereoisomer 33 with Zn and AcOH furnishes (1S,2S)-1,4-diphenylcyclohex-3-ene-1,2-diol. The crystal structures of 11–13 and 16 are obtained by X-ray analysis. The reaction courses of 10 and the other chiral cyclohexanones with prochiral
1,4-二苯基-2,3-二氧杂双环[2.2.1]庚-5-烯(2),在催化量为-78°的CH 2 Cl 2中用催化量的三甲基甲硅烷基三氟甲磺酸盐(Me 3 SiOTf)处理,发生反应用过量的(-)-薄荷酮(10)得到(1 S,2 S,4'a S,5 R,7'a S)-4'a,7'a-二氢-2-异丙基-5-甲基-6',7'- diphenylspiro [环己烷-1,3' - [7' ħ ]环戊[1,2,4] trioxine](11)和它的(1 - [R,2小号,4'A - [R,5 R,7'a R)-非对映异构体12以1:1的比例和21%的收率。以1.1当量重复反应。的Me 3 SiOTf相对于2只得到11,12,及(1级小号,2小号,3'A。ř,5 - [R,6'a小号)-3'a,6'a二氢-2-异丙基5-甲基3'A -苯氧基-5'-苯基螺[环己烷1,2' - [4' ħ ]环戊二烯并[1