|Budget Amount *help
¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 1997 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1996 : ¥1,400,000 (Direct Cost : ¥1,400,000)
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.