Derivatizing agents from phosphorus trichloride and terpenyl tartrates for determining the enantiomeric purity of alcohols

Heterocyclic phosphorous acid chlorides, prepared from C2-symmetric menthyl, borneyl, or fenchyl tartrates and phosphorus trichloride, are inexpensive derivatizing agents for determining the enantiomeric purity of alcohols via phosphorus NMR. The most versatile agent identified from this study, a (1R,2S,5R)-menthyl (R,R)-tartrate-derived 2-chloro-1,3,2-dioxaphospholane, gives, upon esterification with chiral alcohols, diastereomeric phosphites showing phosphorus NMR-shift dispersions between 0.1 ppm and 1.5 ppm.

Figure optionsDownload as PowerPoint slide

2-Chloro-(4R,5R)-bis{[(1R,2S,5R)-2-isopropyl-5-methylcyclohex-1-yl]oxycarbonyl}-1,3,2-dioxaphospholaneC24H40ClO6P[α]D25=-155.0 (c 1.00, THF)Source of chirality: commercial (1R,2S,5R)-menthol and (R,R)-tartaric acidAbsolute configuration: (4R,5R) (1R,2S,5R)

2-Chloro-(4S,5S)-bis{[(1R,2S,5R)-2-isopropyl-5-methylcyclohex-1-yl]oxycarbonyl}-1,3,2-dioxaphospholaneC24H40ClO6P[α]D25=+21.3 (c 1.00, THF)Source of chirality: commercial (1R,2S,5R)-menthol and (S,S)-tartaric acidAbsolute configuration: (4S,5S) (1R,2S,5R)

2-Chloro-(4S,5S)-bis{[(1S,2R,5S)-2-isopropyl-5-methylcyclohex-1-yl]oxycarbonyl}-1,3,2-dioxaphospholaneC24H40ClO6P[α]D25=+151.4 (c 1.00, THF)Source of chirality: commercial (1S,2R,5S)-menthol and (S,S)-tartaric acidAbsolute configuration: (4S,5S) (1S,2R,5S)

2-Chloro-(4R,5R)-bis{[(1S,2R,5S)-2-isopropyl-5-methylcyclohex-1-yl]oxycarbonyl}-1,3,2-dioxaphospholaneC24H40ClO6P[α]D25=-20.6 (c 1.00, THF)Source of chirality: commercial (1S,2R,5S)-menthol and (R,R)-tartaric acidAbsolute configuration: (4R,5R) (1S,2R,5S)

2-Chloro-(4R,5R)-bis{[(1S,2R,4S)-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl]oxycarbonyl}-1,3,2-dioxaphospholaneC24H36ClO6P[α]D25=-105.0 (c 1.00, THF)Source of chirality: commercial (1S,2R,4S)-menthol and (R,R)-tartaric acidAbsolute configuration: (4R,5R) (1S,2R,4S)

2-Chloro-(4R,5R)-bis{[(1R,2R,4S)-1,3,3-trimethylbicyclo[2.2.1]hept-2-yl]oxycarbonyl}-1,3,2-dioxaphospholaneC24H36ClO6P[α]D25=-17.0 (c 1.00, THF)Source of chirality: commercial (1R,2R,4S)-fenchol and (R,R)-tartaric acidAbsolute configuration: (4R,5R) (1R,2R,4S)

Methyl (6S)-2-acetylamino-6-hydroxy-6-phenylhex-2-enoateC15H19NO4[α]D25=+10.0 (c 1.00, EtOH)Source of chirality: lipase-catalyzed desymmetrization of racemic O-(1-phenylpent-4-en-1-yl) acetateAbsolute configuration: (6S)