Synthesis of (S)- and (R)-3-hydroxyhexadecanoic acid

Diol (R)-(+)-3 is prepared either from the hydroxyketone 2 by reduction with fermenting baker's yeast or by hydrolysis of the dioxolane (R)-(+)-1 which is available from dimethyl D-malate as starting material. (R)-(+)-3 could be converted stereoselectively into (R)(+)-4. Reaction of(+)-4 with dodecylmagnesium bromide yielded the alcohol (S)-(-)-5 with >99% ee. Its acetylation gave (S)-(+)-6 and hydrogenolysis gave the primary alcohol (S)-(+)-7 which could be oxidized selectively to (S)-(+)-8 with NaIO4/RuCl3. Alkaline hydroysis of(+)-8 yielded 3-hydroxyhexadecanoic acid (S)-(+)-9 which could be esterified to give the methyl ester (S)-(+)-10 with >99% ee. Starting with the dioxolane (S)-(-)-1, derived from dimethyl L-malate, the 3-hydroxyhexadecanoic acid (R)-(-)-9 and its methyl ester (R)-(-)-10 could be synthesized via the intermediates (S)-(-)-3, (S)-(-)-4, (R)-(+)-5, (R)-(-)-6, (R)-(-)-7 and (R)-(-)-8. Copyright (C) 1996 Elsevier Science Ltd