The first enantiospecific synthesis of (+)-10,11-epoxythapsan-10-ol: revision of the absolute stereochemistry of thapsanes

The first enantiospecific synthesis of (+)-cis,anti,cis-1,8,12,12-tetramethyl-4-oxatricyclo[6.4.0.02,6]dodecan-3-ol (+)-1g, an enantiomer of natural thapsane isolated from Thapsia villosa var minor, is accomplished starting from (R)-carvone, which revises the absolute stereochemistry of natural thapsanes.