A functionalized spiro[4.5]decane framework was synthesized by the Claisen rearrangement of 4-substituted bicyclic dihydropyrans in a highly stereoselective fashion.
Claisen Rearrangement Strategy in Alkenyl Dihydropyran Leading to Total Synthesis of (+)-α-Vetispirene and (−)-Agarospirol
作者:Atsuo Nakazaki、Susumu Kobayashi
DOI:10.1246/cl.2007.42
日期:2007.1
Total synthesis of (+)-α-vetispirene and (-)-agarospirol based on a Claisen rearrangement has been achieved. This is the first example of a Claisen rearrangement in an enantio-enriched alkenyl bicyclic dihydropyran system with perfect asymmetric transmission.
Total Synthesis of (.+-.)-Gleenol and (.+-.)-Axenol via a Functionalized Spiro[4.5]decane
作者:Atsuo Nakazaki、Tomohiro Era、Susumu Kobayashi
DOI:10.1248/cpb.55.1606
日期:——
was accomplished through a readily available spiro[4.5]decane. The key features of the synthesis of 1 and 2 include Claisen rearrangement to afford the multi-functionalized spiro[4.5]decane 4 as a single diastereomer in excellent yield, installation of the C7 isopropyl group via ketene dithioacetal instead of direct alkylation and a diastereoselective reduction of ketone under the Birch conditions.