The synthesis of hermitamides A (1) and B (2) depicted in
Scheme 1 commenced from n-octanal. Vinylation of n-octanal 4
with vinyl magnesium bromide gave allylic alcohol 5 in 92% yield.
Oxidation of the secondary allylic alcohol 5 with IBX in DMSO
afforded enone 6 in 96% yield. Asymmetric reduction of ketone 6
using CBS catalyst gave the chiral allylic alcohol (S)-5 in 80% yield
with high enantiomeric excess (>99%).10 Methylation of (S)-5 using
Meerwein’s reagent (Me3OBF4) in DCM at 0 C to room temperature
furnished compound 7 in 80%. Hydroboration of the terminal
olefin in compound 7 using BH3DMS in THF followed by oxidation
with hydrogen peroxide afforded the primary alcohol 8 in 83% yield