Synthesis of enantiopure structured triacylglycerols

The synthesis of nine enantiopure structured triacylglycerols (TAGs) of the AAB type is described, all possessing the (S)-absolute configuration. Six of them possess one saturated and two identical unsaturated fatty acyl chains, whereas the remaining three possess two identical saturated fatty acids along with one unsaturated fatty acid. The former group was synthesized by a five-step chemoenzymatic route involving a highly regioselective immobilized Candida antarctica lipase, starting from enantiopure (R)-solketal. The second group was prepared by a fully chemical five-step approach based on the same chiral precursor. Such enantiopure TAGs are strongly required as standards for the enantiospecific analysis of intact TAGs in fats and oils.

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3-Decanoyl-1,2-di(cis-octadec-9-enoyl)-sn-glycerolC49H90O6[α]D20=-0.111 (c 9.0, benzene)Source of chirality: (R)-solketal (99% ee)Absolute configuration: (S)

3-Hexadecanoyl-1,2-di(cis-hexadec-9-enoyl)-sn-glycerolC51H94O6[α]D20=-0.055 (c 9.1, benzene)Source of chirality: (R)-solketal (99% ee)Absolute configuration: (S)

3-Hexadecanoyl-1,2-di(cis-octadec-9-enoyl)-sn-glycerolC55H102O6[α]D20=-0.041 (c 8.7, benzene)Source of chirality: (R)-solketal (99% ee)Absolute configuration: (S)

3-Hexadecanoyl-1,2-di(cis-octadec-9,12-dienoyl)-sn-glycerolC55H98O6[α]D20=-0.045 (c 9.0, benzene)Source of chirality: (R)-solketal (99% ee)Absolute configuration: (S)

3-Eicosanoyl-1,2-di(cis-octadec-9-enoyl)-sn-glycerolC59H110O6[α]D20=-0.028 (c 7.2, benzene)Source of chirality: (R)-solketal (99% ee)Absolute configuration: (S)

3-Docosanoyl-1,2-di(cis-octadec-9-enoyl)-sn-glycerolC61H114O6[α]D20=-0.027 (c 5.1, benzene)Source of chirality: (R)-solketal (99% ee)Absolute configuration: (S)

2,3-Dihexadecanoyl-1-cis-octadec-9-enoyl-sn-glycerolC53H100O6[α]D20=-0.035 (c 8.7, benzene)Source of chirality: (R)-solketal (99% ee)Absolute configuration: (S)

2,3-Dihexadecanoyl-1-cis-octadec-9,12-dienoyl-sn-glycerolC53H98O6[α]D20=-0.053 (c 9.5, benzene)Source of chirality: (R)-solketal (99% ee)Absolute configuration: (S)

2,3-Dioctadecanoyl-1-cis-octadec-9-enoyl-sn-glycerolC57H108O6[α]D20=-0.044 (c 9.1, benzene)Source of chirality: (R)-solketal (99% ee)Absolute configuration: (S)

3-Decanoyl-sn-glycerolC13H26O4[α]D20=-3.46 (c 5.1, THF)Source of chirality: (R)-solketal (99% ee)Absolute configuration: (R)

3-Hexadecanoyl-sn-glycerolC19H38O4[α]D20=-2.58 (c 5.2, THF)Source of chirality: (R)-solketal (99% ee)Absolute configuration: (R)

3-Eicosanoyl-sn-glycerolC23H46O4[α]D20=-1.89 (c 5.2, THF)Source of chirality: (R)-solketal (99% ee)Absolute configuration: (R)

3-Docosanoyl-sn-glycerolC25H50O4[α]D20=-1.61 (c 5.1, THF)Source of chirality: (R)-solketal (99% ee)Absolute configuration: (R)

2,3-Dihexadecanoyl-sn-glycerolC35H68O5[α]D20=-4.23 (c 5.1, THF)Source of chirality: (R)-solketal (99% ee)Absolute configuration: (R)

2,3-Dioctadecanoyl-sn-glycerolC39H76O5[α]D20=-3.87 (c 5.1, THF)Source of chirality: (R)-solketal (99% ee)Absolute configuration: (R)