u201c tame hexa u201d molecule the compounds are especially useful for forming chelation complexes with metal ions including radioisotopes application_number US 58219504 A description a suspension of pentaerythritol 1 3 g 9 5 mmol in 15 ml of dry pyridine was stirred well and benzoyl chloride 3 6 ml 31 mmol was added to it slowly at room temperature with stirring after 3 hours of stirring 120 ml of water were added and the mixture was extracted with 120 ml of ethyl acetate to yield an organic layer and an aqueous one the organic layer was washed with a 5 hcl solution 100 ml and 100 ml of water dried over mgso 4 and evaporated the residue was purified via flash chromatography on a silica column using toluene acetone in a 10 1 ratio a viscous colorless oil 1 9 g resulted 4 3 mmol 45 yield 1 h nmr data 250 mhz cdcl 3 were u03b4 2 76 t 1h 3 j 6 8 hz ch 2 oh 3 68 d 2h 3 j 6 8 hz ch 2 oh 4 60 s 6h c ch 2 o 3 7 38 8 04 m 15h 3ph c 26 h 24 o 7 h 2 o 466 5 calc c 66 94 h 5 62 found c 66.