A new practical synthesis of (+)-grandisol from (+)-citronellol using an intramolecular carbenoid cyclization
作者:Hugo J. Monteiro、Julio Zukerman-Schpector
DOI:10.1016/s0040-4020(96)00175-5
日期:1996.3
A new practical 10 step synthesis of (1S,2R)-2-acetyl-1-methylcyclobutaneacetic acid 15 is reported, which has as a key step a rhodium catalyzed intramolecular carbenoid cyclization of the α-diazo-β-ketosulfone 5, readily available from (+)-citronellol 2. Since 15 has already been converted into (+)-grandisol 1, the major pheromone of the cotton boll-weevil Anthonomus grandis, the described preparation
Unusual o-alkylation with iodomethyltrimethylsilane
作者:T. K. Chakraborty、G. V. Reddy
DOI:10.1039/c39890000251
日期:——
Iodomethyltrimethylsilane alkylates alkoxide ions giving rise to O-methyl and O-trimethylsilyl ethers which are formed by cleavage of the silicon–carbon bond.
碘甲基三甲基硅烷烷基化烷氧基离子,生成O-甲基和O-三甲基甲硅烷基醚,它们是通过硅碳键断裂形成的。
US9403791B1
申请人:——
公开号:US9403791B1
公开(公告)日:2016-08-02
A novel synthetic method for optically active terpenes by the ring-opening reaction of (R)-(+)-β-methyl-β-propiolactone
or (S)-ar-turmerone is prepared in high enantiomeric excess from an intermediate, (R)-(+)-citronellic acid or (S)-(+)-3-p-tolylbutyric acid, which is easily prepared by the Sn2 type of ring opening reaction of (R)-(+)-β-methyl-β-propiolactone with homoprenylmagnesium bromide in the presence of a copper(I) salt or di-p-tolylcuprate.
The synthesis of the C14-C23 macrocyclic subunit of cytochalasin B from pulegone is described. The key feature of this synthesis is the photo-inducedrearrangement of epoxydiazomethylketone E to a γ-hydroxy alkenoic ester (Scheme 2). The intermediate epoxy alcohol F was prepared using the asymmetric Sharpless epoxidation. Considerable attention was given to the preparation of allylic alcohol 14,