Total synthesis of macrosphelides B and A

An efficient total synthesis of macrosphelide B has been developed in which the C(5)–O(10) and the C(11)–O(16) fragments were prepared from (S)-1-(2-furyl)ethanol of >98% ee via oxidation of the furan part. In addition, macrosphelide B was transformed stereoselectively into macrosphelide A by reduction followed by Mitsunobu inversion.