An efficient totalsynthesis 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.
Furan Ring Oxidation Strategy for the Synthesis of Macrosphelides A and B
作者:Yuichi Kobayashi、G. Biju Kumar、Tomoaki Kurachi、Hukum P. Acharya、Takashi Yamazaki、Tomoya Kitazume
DOI:10.1021/jo001495d
日期:2001.3.1
degrees C gave a 2 approximately 1:1 mixture of anti/syn alcohols. On the contrary, reduction with NaBH(4) in MeOH at -15 degrees C produced the syn isomer 23 with >10:1 diastereoselectivity. Mitsunobu inversion of the resulting C(14)-hydroxyl group and deprotection of the MOM group with TFA afforded 1. Similarly, reduction of 2 with NaBH(4) afforded the C(14)-epimer of 1 stereoselectively. The observed