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[摘要]：Syntheses of several new functionalized cage compds. are described. The key steps of the reaction sequence are addn. of lithiated methoxyallene to cage diketone I (R1R2 = R3R4 = O), prepn. of dehydrated intermediate I [R1 = R4 = C(OMe):C:CH2; R2R3 = O (II)], and ozonolysis leading to diester I (R1 = R4 = CO2Me; R2R3 = O). Alternatively, II could be hydrolyzed to provide cage compd. I (R1 = R4 = COCH:CH2; R2R3 = O) with a bis-enone subunit. Via diol I (R1 = R4 = CH2OH, R2R3 = O), a chiral crown ether could be prepd. in low yield using 1,1'-binaphthalene-2,2'-diol bis[2-(mesyloxy)ethyl] ether. A stereoselective epoxidn. of chalcone with tert-Bu hydroperoxide in the presence of the above crown ether gave the resp. epoxide in reasonable yield, but with low enantioselectivity. |
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