Stereoselective synthesis of ophiocerins A and C

An efficient synthesis of ophiocerins A and C has been achieved via a common intermediate. The stereogenic centers were generated by means of Jacobsen’s hydrolytic kinetic resolution and Sharpless kinetic resolution.

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(2R)-1-(Oxiran-2-yl)propan-2-olC5H10O2[α]D25=-10.85 (c 0.86, CHCl3)Source of chirality: hydrolytic kinetic resolutionAbsolute configuration : (2R)

(3S,5R)-5-((tert-Butyldimethylsilyl)oxy)-hex-1-en-3-olC12H26O2Si[α]D25=-30.3 (c 1.1, CHCl3)Source of chirality: hydrolytic kinetic resolution and Sharpless kinetic resolution of secondary alcoholAbsolute configuration : (3S,5R)

(1R,3R,)-3-((tert-Butyldimethylsilyl)oxy)-1-((S)-oxiran-2-yl) butan-1-olC12H26O3Si[α]D25=-28.2 (c 0.5, CHCl3)Source of chirality: hydrolytic kinetic resolution and Sharpless kinetic resolution of secondary alcoholAbsolute configuration : (1R,3R,1’S)

(3S,4R,6R)-6-((tert-Butyldimethylsilyl)oxy)hept-1-ene-3,4-diolC13H28O3Si[α]D25=-11.3 (c 1.2, CHCl3)Source of chirality: hydrolytic kinetic resolution and Sharpless kinetic resolution of secondary alcoholAbsolute configuration : (3S,4R,6R)

tert-Butyl-((R)-1-(((4R,5S)-2,2–dimethyl-5-vinyl-1,3-dioxolan-4-yl)-propan-2-yl)oxy)dimethylsilaneC16H32O3Si[α]D25=-2.35 (c 0.34, CHCl3)Source of chirality: hydrolytic kinetic resolution and Sharpless kinetic resolution of secondary alcoholAbsolute configuration : (4R,5S,1’R)

((4S,5R)-5-((R)-2-((tert-Butyldimethylsilyl)oxy)propyl)-2,2-dimethyl-1,3-dioxolan-4-yl)methanolC15H32O4Si[α]D25=-12.2 (c 1.2, CHCl3)Source of chirality: hydrolytic kinetic resolution and Sharpless kinetic resolution of secondary alcoholAbsolute configuration : (4S,5R,2’R)

((4S,5R)-5-((R)-2-Hydroxypropyl)-2,2-dimethyl-1,3-dioxolan-4-yl)methyl 4-methylbenzenesulfonateC16H24O6S[α]D25=-6.0 (c 0.43, CHCl3)Source of chirality: hydrolytic kinetic resolution and Sharpless kinetic resolution of secondary alcoholAbsolute configuration : (4S,5R,2’R)

(1S,3R,)-3-((tert-Butyldimethylsilyl)oxy)-1-((S)-oxiran-2-yl) butan-1-olC12H26O3Si[α]D25=-18.1 (c 3.2, CHCl3)Source of chirality: hydrolytic kinetic resolution and Sharpless asymmetric epoxidationAbsolute configuration : (1S,3R,1’S)

(3S,4S,6R)-6-((tert-Butyldimethylsilyl)oxy)hept-1-ene-3,4-diolC13H28O3Si[α]D25=-28.6 (c 0.8 CHCl3)Source of chirality: hydrolytic kinetic resolution and Sharpless asymmetric epoxidationAbsolute configuration : (3S,4S,6R)

tert-Butyl-(((R)-1-((4S,5S)-2,2–dimethyl-5-vinyl-1,3–dioxolan-4-yl)-propan-2-yl)oxy)dimethylsilaneC16H32O3Si[α]D25=-16.9 (c 0.4, CHCl3)Source of chirality: hydrolytic kinetic resolution and Sharpless asymmetric epoxidationAbsolute configuration : (4S,5S,1’R)

((4S,5S)-5-((R)-2-((tert-Butyldimethylsilyl)oxy)propyl)-2,2-dimethyl-1,3-dioxolan-4-yl)methanolC15H32O4Si[α]D25=-22.6 (c 0.2, CHCl3)Source of chirality: hydrolytic kinetic resolution and Sharpless asymmetric epoxidationAbsolute configuration : (4S,5S,2’R)

((4S,5S)-5-((R)-2-Hydroxypropyl)-2,2-dimethyl-1,3-dioxolan-4-yl)methyl 4-methylbenzenesulfonateC16H24O6S[α]D25=+3.2 (c 0.3, CHCl3)Source of chirality: hydrolytic kinetic resolution and Sharpless asymmetric epoxidationAbsolute configuration : (4S,5S,2’R)