Application of intramolecular Heck reactions to the preparation of steroid and terpene intermediates having cis A-B ring fusions. Model studies for the total synthesis of complex cardenolides.
作者:Sabine Laschat、Frank Narjes、Larry E. Overman
DOI:10.1016/s0040-4020(01)80759-6
日期:1994.1
cyclization of the aryl triflate 21. This latter conversion demonstrates that allylic ether substitution is compatible with intramolecular Heck chemistry and suggests applications of this chemistry in the synthesis of highly oxidized cardenolides.
顺式稠合的三环二烯酮13是由二烯基三氟甲磺酸酯12的分子内Heck环化形成的主要产物(方案I)。类似地,顺式六氢菲啶22是由三氟甲磺酸芳基酯21的Heck环化以良好的产率形成的。后一种转化表明烯丙基醚取代与分子内Heck化学相容,并暗示了该化学在高度氧化的烯醇内酯合成中的应用。