Alkylation of benzyl, cyclopropylmethyl and allyl acetates with trialkylaluminum. A stereochemical study

✍ Scribed by Akira Itoh; Koichiro Oshima; Shizuka Sasaki; Hajime Yamamoto; Tamejiro Hiyama; Hitosi Nozaki

• Publisher: Elsevier Science
• Year: 1979
• Tongue: French
• Weight: 251 KB
• Volume: 20
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)86701-0

✦ Synopsis

The title reaction is found synthetically useful and the stereochemical study has revealed that carbocationic intermediates are involved in the reaction of endo-2-acetoxynorcarane, its epimer, and acetates of cis-and &on.5-carveol with trimethylaluminum. Alkylation' of alcoholic substrates R'OH v& the esters R'OCOR with organomztallic reagents R2Mtl to produce R'-R2 encounters the problem that the reagents preferentially attack the ester carbony12, often transforming the substrates to relatively unstable halides prior to alkylation. In contrast, trialkylaluminum compounds3 react with certain allylic acetates to give the corresponding alkylated products as has been reported briefly.4 This C-C bond formation5 is now extended not only to ally1 but benzyl and cyclopropylmethyl acetates and is found to be characterized by ctiboctinic ti~editi being phoduced 6hom e~Xe.h~ in nonpoti oh &A po&vt AO.b~ntd buch a6 hexme Oh dickeohom&ane.