Tungsten-Promoted Intramolecular Alkoxycarbonylation for Synthesis of Complex Oxygenated Molecules
详细信息 查看全文
- 作者：Chi-Chung Chen ; Jang-Shyang Fan ; Su-Ju Shieh ; Gene-Hsian Lee ; Shie-Ming Peng ; Sue-Lang Wang ; and Rai-Shung Liu
- 刊名：Journal of the American Chemical Society
- 出版年：1996
- 出版时间：October 2, 1996
- 年：1996
- 卷：118
- 期：39
- 页码：9279 - 9287
- 全文大小：884K
- 年卷期：v.118,no.39(October 2, 1996)
- ISSN：1520-5126
文摘
Intramolecular alkoxycarbonylation of tungsten-propargylcompounds proceeds with excellent diastereoselectivities to form 
3-
- and -
-lactones but for
-lactones. With OSi(t-Bu)Me2substituted for an 
-hydroxygroup, 3--lactones are stereoselectivelyformed with syn stereoselection.An optically active tungsten3--lactoneis prepared from D-(+)-xylose to illustrate thestereochemical effect of OSi(t-Bu)Me2.All these 3--, --, and--lactones are converted to allyl anions that react insitu with aldehydes and ketones to produce various
-(hydroxylalkyl)--methylene--lactones with gooddiastereoselectivity. This reaction is also applied to thesynthesisof chiral -methylene butyrolactones. Organic carbonyls add tothe 
-allyl groups of 3-- and --lactonesoppositethe tungsten fragment, whereas additions occur from the metal side for3--lactones. The stereochemicalcoursesof these reactions are discussed in detail. These twotungsten-promoted reactions efficiently effectstereoselectivetransformation of chloroalkynols to complex -methylene--lactones,which are useful materials for syntheses oftrisubstituted 1,3-, 1,4-, and 1-5-diols.
3-- and --lactones but for-lactones. With OSi(t-Bu)Me2substituted for an -hydroxygroup, 3--lactones are stereoselectivelyformed with syn stereoselection.An optically active tungsten3--lactoneis prepared from D-(+)-xylose to illustrate thestereochemical effect of OSi(t-Bu)Me2.All these 3--, --, and--lactones are converted to allyl anions that react insitu with aldehydes and ketones to produce various-(hydroxylalkyl)--methylene--lactones with gooddiastereoselectivity. This reaction is also applied to thesynthesisof chiral -methylene butyrolactones. Organic carbonyls add tothe -allyl groups of 3-- and --lactonesoppositethe tungsten fragment, whereas additions occur from the metal side for3--lactones. The stereochemicalcoursesof these reactions are discussed in detail. These twotungsten-promoted reactions efficiently effectstereoselectivetransformation of chloroalkynols to complex -methylene--lactones,which are useful materials for syntheses oftrisubstituted 1,3-, 1,4-, and 1-5-diols.