合成路线1

The condensation of the choral oxazolidinone (I) with octanal (II) by means of Bu2B-OTf and TEA in dichloromethane gives the chiral alcohol (III), which is protected with DHP and PPTS, yielding the tetrahydropyranyl ether (IV). The cleavage of the chiral adjuvant of (IV) by means of LiOH and H2O2 affords the carboxylic acid (V), which is esterified with (2S)-hydroxy-3-methylbutyric acid benzyl ester (VI) by means of trichlorobenzoyl chloride and TEA to provide the adduct (VII). Elimination of the tetrahydropyranyl protecting group of (VII) by means of Ts-OH gives the hydroxyester (VIII), which is condensed with the chiral amino acid (IX) by means of trichlorobenzoyl chloride as before to yield the triester compound (X). Elimination of the Mom protecting group of (X) by means of Tms-Cl and tetrabutylammonium bromide affords the hydroxy compound (XI), which is hydrogenated with H2 over Pd(OH)2 to provide the carboxylic acid (XII). Elimination of the Boc protecting group of (XII) by means of TFA gives the amino acid (XII), which is finally submitted to a macrocyclization by means of DPPA and DIEA in DMF to yield the target hapalosin.