Use Of Synthetic Vitamin E Side Chain And Its Related Compounds Of The Steroidal Sapogenin Degradation Of Waste

The method for degradation of steroidal sapogenins with hydrogen peroxide developed by our research group is milder and less contaminative than the classic one using CrO3 as the degradation reagent. This new method also improved the yield of the degradation and at the same time, optically pure (R)-4-methylvalerolactone, a new chiral source which can be used in the synthesis of many natural products containing chiral methyl was obtained from the residue of degradation of steroidal sapogenins.This dissertation dealed with synthesis of some natural products containing chiral methyl in their molecules using (R)-4-methylvalerolactone and (R,R)-4-methyl-2-hydroxylvalerolactone as the starting material.There are four parts in this dissertation.1. A few mature ways of preparation t of small molecule compounds were developed for making good use of (R)-4-methylvalerolactone and (R,R)-4-methyl-2-hydroxylvalerolactone. They are transformed into stable small molecules, which can be used as starting materials in the synthesis of other compounds.2. Using (R)-methyl-5-(tert-butyldimethylsilyloxy)-4-methylpentanoate as the starting material, through the LiAlH4 reduction, iodization, coupling, deprotection of TBS, iodization, wittig reaction, and hydrogenation eight-step reaction,52% total yield, optical active vitamin side chain has been synthesized.3. Using (2R,4R)-5-((tert-butyldimethylsilyl)oxy)-4-methylpentane-1,2-diol as the starting material, exploring a route to the synthesis of (+)-Menthofuran. Six-membered ring has been built, the synthesis of five-membered ring is under exploration..