A Novel and Selective Desilylating Method for Trialkylsiltl Ethers and Enzymatic Resolution of (E)-r-Tributylstannyl Allylic Alcohol and It''s Application in Drug Synthesis
博士 === 淡江大學 === 化學學系 === 86 === Part I: Trimethylsilyl ethers (0.25M) are deprotected to theirs correspondingalcohols in CCl4/CH3OH (v/v=1:1) under sonication for 15 minutes in a commercialultrasonic cleaning bath (39kHz). The selective deprotection of...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Others |
| Language: | zh-TW |
| Published: |
1998
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| Online Access: | http://ndltd.ncl.edu.tw/handle/76415214719107093822 |
| Summary: | 博士 === 淡江大學 === 化學學系 === 86 === Part I: Trimethylsilyl ethers (0.25M) are deprotected to
theirs correspondingalcohols in CCl4/CH3OH (v/v=1:1) under
sonication for 15 minutes in a commercialultrasonic cleaning
bath (39kHz). The selective deprotection of tert-butyldimethyl-
silyl ethers of primary alcohols is achieved under ultrasonic
condition (Scheme I). A series of tert-butyldimethylsilyl,
triisopropylsilyl, tert-butyldi-phenylsilyl ethers are converted
to theirs corresponding alcohols in CBr4/CH3OH (0.1eq/10 mL)
reaction system under refluxing condition(Scheme II). The
chemoselectivity can be achieved between primary
andsecondarytriisopropylsilyl ether when more hindered
2-propanol is used instead of methanol.Part II: Lipase AK (from
Pseudomonase sp.) catalyzed the enantio-
selectivetransesterification of racemic (E)-g-tributylstannyl
allylic alcohols 37 with vinyl acetate in hexane (SchemeIII).
The enantiomericexcess of the allylic alcohols were determined
by 19F-NMR analysis of theirs correspondingMosher*s esters.The
optically active alcohol (S)-37a was protected to
triethylsilylether and it was further applied in total synthesis
of PGE1 methyl ester (Scheme IV).
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