The total synthesis of (±)-pinguisone and (±)-deoxopinguisone, the unusual [5–6], fused-ring sesquiterpenes, was accomplished by the photochemical transformation of the bicyclo [3.2.2]non-6-en-2-one into the bicyclo [4.3.0]non-4-en-7-one.
Rearrangement Approaches to Cyclic Skeletons. IV. The Total Synthesis of (±)-Pinguisone and (±)-Deoxopinguisone Based on Photochemical [1,3] Acyl Migration of a Bicyclo[3.2.2]non-6-en-2-one
作者:Tadao Uyehara、Yasuhiro Kabasawa、Tadahiro Kato
DOI:10.1246/bcsj.59.2521
日期:1986.8
2-chloroacrylonitrile. Ring enlargement of 9 using (CH3)3SiCHN2 and BF3 etherate gave the corresponding bicyclo[3.2.2]oct-6-en-2-one (8). The photochemical [1,3] acyl migration of 8 gave the [5–6] fused-ring compound (7). The fourth methyl was introduced selectively by the conjugate addition of (CH3)2CuLi to the spiro[bicyclo[4.3.0]non-8-ene-3,2′-[1,3]dioxolan]-7-one prepared from 7. Each furan ring of 2 and 3 was