New chiral sources for asymmetric synthesis

通过该项目获得了以下结果：1) pfl催化水解不对称诱导生成中-1,3-二乙酰氧基-5-环庚烯，使单乙酸(1S,3R)-6的对映体过量量达到97% (e.e)，在美维酸衍生物中转化为相当于δ内酯部分的合成物。2)荧光假单胞菌脂肪酶对中旋二醇进行不对称酯交换反应，得到相应的高对映体过量的单乙酸酯，从而正式合成(-)-姜黄醇内酯A。3)利用呋喃环转移反应和碱催化pinacol型重排，改进了本研究的合成路线，合成了从蘑菇担子菌中分离得到的内酰胺类倍半萜furroscobiculin B。4)荧光假单胞菌脂肪酶催化中-2,5-二（乙酰氧基甲基）-3,4-（异丙基二氧基）四氢呋喃的不对称水解，得到相应的光学活性为92%的单乙酸酯，收率为94%。通过与D-allose的化学对比，确定其绝对构型为2S、3S、4R、5R。5)经酶催化制备的具有光学活性的5-环辛烯-1,2-二醇衍生物，通过立体中心与离去基连接的完全反转的跨环反应转化为双环[3.3.0]辛烷衍生物。以（S，S） -5-环烯-1,2-二醇为起始原料，用该方法合成了(+)-环环霉素。

Following results were obtained through this project.1) Asymmetric induction into meso-1,3-diacetoxy-5-cycloheptene by PFL-catalyzed hydrolysis afforded monoacetate (1S,3R)-6 of 97% enantiomeric excess (e.e.), which was converted into a synthetic equivalent of delta-lactone moiety in mevinic acid derivatives.2) Asymmetric transesteriflcation of meso-spirodiol using Pseudomonas fluorescens lipase gave the corresponding monoacetate of high enantiomeric excess, from which the formal synthesis of (-) -curcumanolide A was achieved.3) Total synthesis of furoscrobiculin B,a lactarane sesquiterpene isolated from basidiomycetes of mushurooms, was achieved via an improved synthetic route of our previous work based on a Furan Ring Transfer reaction and base-catalyzed pinacol-type rearrangement.4) Pseudomonas fluorescens lipase-catalyzd asymmetric hydrolysis of meso-2,5-bis (acetoxymethyl) -3,4- (isopropylidenedioxy) tetrahydrofuran afforded the optically active correponding monoacetate of 92% e.e. in 94% yield. The absolute configuration was determined to be 2S,3S,4R,5R by chemical correlation with D-allose.5) Optically active 5-cyclooctene-1,2-diol derivatives prepared by enzymatic procedure have been converted into bicyclo [3.3.0] octane derivatives by transannular reaction with complete inversion of stereogenic center attached by a leaving group. Formal synthesis of (+) -iridomyrmecin has been achieved starting from (S,S) -5-cyclooctene-1,2-diol by using this process.