Oxaspiropentyl ketones and acetals prepared from α-cyclopropylidene ketones and acetals undergo, with lithium halides, isomerisation to 2-acylcyclobutanones and monoacetals.
Tandem Michael–Nucleouphilic Addition of 2‐Cyclopropylidene Propionaldehyde—A Novel Method for the Synthesis of Spirocyclopropane‐Annulated Heterocycles
作者:Xian Huang、Lei Yu、Zhen‐Hua Chen
DOI:10.1081/scc-200054852
日期:2005.5
Abstract 8‐Methyl‐4‐thia‐6‐aza‐spiro[2.5]oct‐5‐en‐7‐ols and 8‐methyl‐4‐selena‐6‐aza‐spiro[2.5]oct‐5‐en‐7‐ols were synthesized in moderate to good yields via tandem Michael–nucleophilic addition of 2‐cyclopropylidenepropionaldehyde under mild conditions.
Synthesis of a Functionalized Carbocyclic Skeleton of Ptaquilosin, the Aglycone of a Bracken Carcinogen Ptaquiloside Based on an Intramolecular Diels–Alder Reaction
A tricyclic compound 13 possessing the carbocyclic skeleton of ptaquilosin (2), the aglycone of a brackencarcinogenptaquiloside (1) has been synthesized by the intramolecular Diels–Alder reaction of trienes 12a and 12b.