Tetrahedron Letters,Vol.27,No.l7,pp 1909-1912,1986 0040-4039/86 $3.00 + .OO Printed in Great Britain ... 2,2-DIHYDRO 2-METHYL 2,2-DIPHENYL 3,4-KETtlANO 1,2-0XAPHOSPHO:ANNE AS NEW REAGENT FOR THE METHYLENATION OF CAREONYL COMPOUNDS ... Laboratoire de Synthese Organique, associi! au CNRS - Universite de Rennes I, Avenue du General Leclerc, 35042 RENNES - FRANCE. ... 2,2-dihydro 2-methyl 2,2-diphenyl 3,4 methano ...