Formal Synthesis of (±)-Indolizidine 209BIndium-promoted Conversion of Allylic Bromide to Alcohol Moiety and Synthesis of Pipermethystine Skeletons

• Main Authors: LIOU,BO-SIAN, 劉柏賢
• Other Authors: CHOU,SHANG-SHING P.
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/67920259671869146932

博士 === 輔仁大學 === 化學系 === 104 === (1) Formal Synthesis of (±)-Indolizidine 209B 　　Compound 28, a stereoisomer of indolizidine 195I, has now been synthesized from compound 27, which was available from our previous research. In addition, compound 25 reacts with pentylmagnesium bromide to give compound 30, which reacted with concentrated HBr solution to yield compound 31. The stereochemistry of compound 31 was determined by X-ray crystallography. Thus we have achieved a formal synthesis of (±)-indolizidine 209B. (2) Indium-promoted Conversion of Allylic Bromide to Alcohol Moiety and Synthesis of Pipermethystine Skeletons 　　We have developed a new method for the synthesis of compound 33 from bromide 32 by reacting with indium to give an organometallic intermediate which could then react with air or an oxaziridine. Several sulfone products 57, 58 and 59 have also been synthesized. Compound 57 has the skeleton of natural product pipermethystine. Desulfonylation of compound 59 with Al/Hg gave compound 60 together with a small amount of the over-reduction product 61.