76492-90-5

Upstream product

• 138320-32-8 (S)-(+)-2-(4-tert-butylbenzyl)-1-chloropropane 
• 141-91-3 cis-2,6-dimethylmorpholine 
• 20753-88-2 meso-((1-hydroxypropan-2-yl)oxy)propan-1-ol 
• 173379-59-4 (S)-(-)-2-(chloromethyl)-2-(4-tert-butylbenzyl)ethanol 
• 172477-52-0 2-(4-tert-butylbenzyl)-1,3-propanediol 
• 79253-37-5 (S)-3-(4-(tert-butyl)phenyl)-2-methylpropan-1-ol 
• 173379-60-7 (S)-(+)-<2-(4-tert-butylbenzyl)-2-(tolylsulfonyloxymethyl)>ethyl acetate 
• 173379-58-3 (S)-(+)-<2-(4-tert-butylbenzyl)-2-chloromethyl>ethyl acetate 
• 173379-57-2 (R)-(+)-<2-(4-tert-butylbenzyl)-2-hydroxymethyl>ethyl acetate 
• 18880-00-7 1-(bromomethyl)-4-(1,1-dimethylethyl)benzene 
• 37765-76-7 2-(4-tert-butylbenzyl)diethylmalonate 

Relevant academic research and scientific papers

Betti's base for crystallization-induced deracemization of substituted aldehydes: synthesis of enantiopure amorolfine and fenpropimorph

The acid-promoted crystallization-induced diastereoisomer transformation (CIDT) of naphthoxazines derived from racemic O-protected 2-substituted 4-hydroxybutyraldehydes and enantiopure Betti's base allows the deracemization of the starting aldehydes with ee up to 96%. As an alternative, reduction with lithium aluminum hydride of the diastereoisomerically enriched naphthoxazines leads to enantioenriched primary amines. The utility of the latter strategy was demonstrated by applying it to the synthesis of enantioenriched fenpropimorph and to the first synthesis of enantiopure amorolfine, with ee up to 99.5%.

Enantioselective chemoenzymatic synthesis of the S-enantiomer of the systemic fungicide fenpropimorph

Chemoenzymatic synthesis of the S-(-)-enantiomer of fenpropimorph (S)-1 in high optical and chemical purity is described. One feature of this process entails the enantioselective acetylation of prochiral 1,3-propanediol 4 by Pseudomonas sp. lipases, and subsequent transformation of the monoacetate (R)-5 into the final product by the selected order of transformations that comprise; chlorination or tosylation under non-racemizing conditions, hydrogenolysis of the resulting chloromethyl or tosyl group in (+)-6 and (+)-8, second chlorination of (-)-9, and alkylation of cis-3,5-dimethylmorpholine by 1-chloropropane derivative (+)-10. This sequence of reactions affords (S)-1, the more active enantiomer in the commercialized racemic mixture with systemic fungicidal activity.

Asymmetrical hydrogenation

There is disclosed a process for the asymmetrical hydrogenation of (E)-2-methyl-3-phenyl-2-propen-1-ol of formula STR1 wherein R1 is as defined herein, to give compounds of formula STR2 The catalyst is a neutral or cationic rhodium complex of a chiral atropisomeric phosphine.