were recorded on a Bruker AVANCE 500 MHz with tetramethylsilane (TMS) as the internal standard for 1H and solvent signals for 13 were measured on a 1100 Agilent LC/MS ion trap. Reactions were monitored by thin-layer chromatography using silica gel G60 F254 (Merck). Silica gel 300-400 mesh (Merk) was used for column Chromatography.