Synthesis of spiroacetal enol ethers via intramolecular conjugate addition of hemiacetal alkoxides to alkynoates
作者:Hiroaki Toshima、Yoshinori Furumoto、Shintaro Inamura、Akitami Ichihara
DOI:10.1016/0040-4039(96)01206-3
日期:1996.8
(E)- and (Z)-2-Methoxycarbonylmethylene-1,6-dioxaspiro[4.5]decane (12E, 12Z) have been constructed from the acyclic keto alcohol 11a possessing an alkynoate part under the basic conditions. By the thermodynamic control, 12E could be obtained in high selectivity. Under several basic and acidic conditions, 12Z could be isomerized to 12E.
(E)-和(Z)-2-甲氧羰基亚甲基-1,6-二氧杂螺[4.5]癸烷(12 E,12 Z)在碱性条件下由具有炔酸部分的无环酮醇11a构成。通过热力学控制,12 ê可以在高选择性获得。在一些碱性和酸性条件下,12 ž可异构化为12 Ë。