Scheme 4.

Borylation of 1 a and 2 a with BBr3 and subsequent protection with pinacol/Et3N or ZnPh2. Right, solid state structure of 7 (hydrogens omitted and ellipsoids at the 50 % probability level).24

Borylation of 1 a and 2 a with BBr3 and subsequent protection with pinacol/Et3N or ZnPh2. Right, solid state structure of 7 (hydrogens omitted and ellipsoids at the 50 % probability level).24