A short and practical synthesis of two Hagen's gland lactones.

A seven-step total synthesis of Hagen's gland lactones 1 and 2 starting from 1,2-O-isopropylidene-alpha-D-xylofuranose 3 is reported. The success of this short and practical synthesis depends on the use of two key reactions: a stereoselective nucleophilic substitution at the anomeric position of 5 and 6, which allowed the construction of the gamma-lactone ring, and an alkyl substitution reaction on tosylated compound 4, which permitted the carbon chain elongation of the tetrahydrofuran ring appendage at C-6.