hz 1h and 12 14 s exchanges with d 2 o 1h anal calcd for c 9 h 10 o 2 s c 59 32 h 5 54 s 17 59 a solution of 3 hydroxy 2 3 methyl 1 oxo 2 buten 1 yl thiophene 39 0 g 0 214 mol and p toluenesulfonic acid 3 5 g 18 mmol in toluene 400 ml was heated to reflux for 3 5 d the resultant solution was washed with saturated aqueous sodium bicarbonate and dried over sodium sulfate the solvent was evaporated in vacuo to give a brown oil 38 62 g 99 a portion of the resultant oil was purified for analysis by distillation in a kugelrohr oven at 145 u00b0 to 155 u00b0 c at 0 35 mm hg to give the product as an amber oil ir neat 2979 1664 1530 and 1442 cm 1 ms m z 183 mh 1 h nmr cdcl 3 u03b41 51 s 6h 2 67 s 2h 6 67 d j 5 4 hz 1h and 7 60 d j 5 4 hz 1h anal calcd for c 9 h 10 o 2 s c 59 32 h 5 54 s 17 69 sodium borohydride 0 97 g 25 5 mmol was added to a solution of 5 6 dihydro.