The Dimesitylboron Group In Organic-Synthesis .3. Reactions Of Allyldimesitylborane

Allyldimesitylborane readily yields an anion that is attacked by electrophiles in a region- and stereospecific fashion. Alkylation is at the γ-position to give trans -vinyl-boranes that can be oxidised to aldehydes. Reaction with trimethylsilyl chloride gives the new, highly differentiated three carbon synthon, Mes 2 BCH t :CHCH 2 SiMe 3 also by γ-attack and reaction with benzaldehyde proceeds similarly to give rise to a novel γ-lactol synthesis.