A novel stereoselective synthesis of pachastrissamine (jaspine B) starting from 1-pentadecanol

A novel stereoselective synthesis of pachastrissamine (jaspine B), starting from commercially available 1-pentadecanol is described. Sharpless asymmetric dihydroxylation and a chelation controlled vinyl Grignard reaction are the key steps in this synthetic strategy.

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(2R,3S)-2,3-Dihydroxyheptadecanoic acid ethyl esterC19H38O4Ee 97%[α]D25=-7.1 (c 0.8, CHCl3)Source of chirality: Sharpless asymmetric dihydroxylationAbsolute configuration: (2R,3S)

(2R,3S)-2,3-Bis(methoxymethoxy)heptadecanoic acid ethyl esterC23H46O6[α]D25=+43.6 (c 1.0, CHCl3)Source of chirality: Sharpless asymmetric dihydroxylationAbsolute configuration: (2R,3S)

(2S,3S)-2,3-Bis(methoxymethoxy)heptadecan-1-olC21H44O5[α]D25=-10.5 (c 1.0, CHCl3)Source of chirality: Sharpless asymmetric dihydroxylationAbsolute configuration: (2S,3S)

(3R,4S,5S)-4,5-Bis(methoxymethoxy)-nonadec-1-en-3-olC23H46O5De >95%[α]D25=+1.85 (c 0.56, CHCl3)Source of chirality: Sharpless asymmetric dihydroxylation, Chelation controlled Grignard reactionAbsolute configuration: (3R,4S,5S)

trans-(4S,5S)-1-Azido-4,5-bis(methoxymethoxy)-nonadec-2-eneC23H45N3O4[α]D25=+8.25 (c 0.15, CHCl3)Source of chirality: Sharpless asymmetric dihydroxylationAbsolute configuration: (4S,5S)

1-(((3R,4R,5S)-4,5-Bis(methoxymethoxy)-nonadec-1-en-3-yloxy)methyl)benzeneC30H52O5[α]D25=-2.1 (c 0.80, CHCl3)Source of chirality: Sharpless asymmetric dihydroxylation, Chelation controlled Grignard reactionAbsolute configuration: (3R,4R,5S)

(2R,3R,4S)-2-(Benzyloxy)-3,4-bis(methoxymethoxy)-octadecan-1-olC29H52O6[α]D25=-15.5 (c 2.0, CHCl3)Source of chirality: Sharpless asymmetric dihydroxylation, Chelation controlled Grignard reactionAbsolute configuration: (2R,3R,4S)

1-(((2R,3R,4S)-1,3,4-Tris(methoxymethoxy)-octadecan-2-yloxy)methyl)benzeneC31H56O7[α]D25=+5 (c 0.5, CHCl3)Source of chirality: Sharpless asymmetric dihydroxylation, Chelation controlled Grignard reactionAbsolute configuration: (2R,3R,4S)

(2R,3S,4S)-1,3,4-Tris(methoxymethoxy)octadecan-2-olC24H50O7[α]D25=-2.3 (c 1.6, CHCl3)Source of chirality: Sharpless asymmetric dihydroxylation, Chelation controlled Grignard reactionAbsolute configuration: (2R,3S,4S)

(2S,3S,4S)-2-Azido-1,3,4-tris(methoxymethoxy)octadecaneC24H49N3O6[α]D25=+7 (c 0.5, CHCl3)Source of chirality: Sharpless asymmetric dihydroxylation, Chelation controlled Grignard reactionAbsolute configuration: (2R,3S,4S)

(2S,3S,4S)-4-Amino-tetrahydro-2-tetradecylfuran-3-ol (jaspine B)C18H37NO2[α]D25=+17.7 (c 0.40, CHCl3)Source of chirality: Sharpless asymmetric dihydroxylation, Chelation controlled Grignard reactionAbsolute configuration: (2S,3S,4S)