First total synthesis of (-)-AL-2.
Treatment of the 3,4-dioxygenated-9-hydroxy-1-nonyn-5-one derivative, derived from diethyl l-tartrate, with a palladium catalyst in methanol under a CO atmosphere effected an intramolecular acetalization and a stereoselective construction of the (E)-methoxycarbonylmethylidene functionality resulting in formation of the core framework of the diacetylenic spiroacetal enol ether natural products. Chemical transformations of the 1,6-dioxaspiro[4.5]decane derivative thus formed led to the first total synthesis of (-)-AL-2. [reaction: see text]
Miyakoshi
Naoki
N
Faculty of Pharmaceutical Sciences, Kanazawa University, Takara-machi, Kanazawa 920-0934, Japan.
Mukai
Chisato
C
D000080:Acetals / Q000737:chemistry*; D019306:Artemisia / Q000737:chemistry; D004852:Epoxy Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010165:Palladium / Q000737:chemistry; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D013644:Tartrates / Q000737:chemistry
D000080:Acetals; D004852:Epoxy Compounds; D013141:Spiro Compounds; D013644:Tartrates; C478877:diacetylenic spiroacetal enol ether epoxide; D010165:Palladium