NEW OPTICALLY-ACTIVE ORGANOTIN COMPOUNDS FOR HETEROGENEOUS BIMETALLICCATALYSIS

Chiral tin(IV) derivatives with two or three chiral centers adjacent t o the metal (-)-Ment(2)SnMe(2), (-)-Ment(2)SnPh(2), (-)-Ment(3)SnCl, ( -)-Ment(3)SnH; (-)-Ment = R,2S,5R)-1-chloro-5-methyl-2-isopropylcycloh exane, R(2)Sn[CH(Me)(n-Hex)](2) (R = Bu or Ph) have been prepared eith er by the coupling of menthylmagnesium chloride with tin halides or by the reaction of lithium stannates with optically active (2-octyl)tosy late. The stereospecificity of both processes was remarkably high, lea ding to new optically pure organotin reagents which have been fully ch aracterized.