Two-component method to enantiopure quinolizidinones and Indolizidinones. Total synthesis of (-)-lasubine II.
The reaction of iodides 1 and enantiopure beta-amino esters 2 mediated by potassium carbonate in acetonitrile at 65 degrees C provides quinolizidinones or indolizidinones 3, together with piperidines or pyrrolidines 4. Hydrolysis of 4 to the corresponding carboxylic acids followed by treatment of acetic anhydride/triethylamine gives 3 in high yields. Using 3a as a key intermediate, (-)-lasubine II is synthesized in four steps. [reaction: see text]
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State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, China.
Zhu
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D007212:Indolizines / Q000737:chemistry*; D011807:Quinolizines / Q000138:chemical synthesis* / Q000737:chemistry*; D013237:Stereoisomerism
D007212:Indolizines; D011807:Quinolizines; C414385:lasubin I