Asymmetric synthesis of methyl (2R,3S)-3-(4-methoxyphenyl) glycidate, a key intermediate of diltiazem, via Mukaiyama aldol reaction
β Scribed by Ritsuo Imashiro; Tooru Kuroda
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- French
- Weight
- 62 KB
- Volume
- 42
- Category
- Article
- ISSN
- 0040-4039
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β¦ Synopsis
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OAc O NMe
π SIMILAR VOLUMES
## Abstract The cyclopropanation of the bislactim ethers 3 with diiodomethanes and diethylzinc proceeds in good yields and with high diastereoselectivities, affording the cyclopropyl bislactim ethers 6. Protection of the hydroxy group and subsequenthydrolysis furnish virtually enantiomerically and
## Abstract The titanium derivative 2 of the bislactim ether 1 of cyclo(βLβValβGlyβ) reacts with aldehydes and ketones 3 highly diastereoselectively to give the __syn__βaddition products 4. Upon hydrolysis with diluted trifluoroacetic acid the compounds 4 yield besides methyl Lβvalinate the (2__R__
The titanium derivative 4a of the bislactim ether l a from cyclo-(L-Val-Gly) reacts with + m a t u r a t e d aldehydes 5 exclusively by 1.2-addition in a highly diastereowlective mode to give virtually only the (2R,l'S) diastereomers of type 6. Upon hydrolysis these furnish the methyl (2R,3S)-thrm-2