42 yield of compound 16 in the form of an oil and 371 mg 0 95 mmol of the tosylate which had not reacted was recovered the obtained oil was heated in 100 ml 80 acetic acid at 80 u00b0 c to complete hydrolysis of the benzylidene moiety the mixture was evaporated and co evaporated with toluene and purified by column chromatography ch 2 cl 2 meoh 90 10 affording 408 mg 1 11 mmol 53 yield of the compound 18 which crystallized out of meoh 1 h nmr dmso d6 u03b4 1 53 2 42 m h 3 h 3 39 2 8 4 2 m 6h 4 53 m 1h 8 47 s h 6 ppm 13 c nmr dmso d 6 u03b4 35 3 c 3 39 51 4 c 2 39 60 7 61 1 c 4 39 c 6 39 67 2 c 1 39 68 3 c 5 82 7 c 5 39 147 9 c 6 150 9 c 2 160 9 c 4 ppm anal c 10 h 13 n 2 o 5 i u00d7 0 75 h 2 o the above compound was synthesized in the same manner from compound 6 but in very moderate yields better results are obtained when the alcohol 8 is used as starting point a suspension of 2 40 g 10 46 mmol of n 3 benzoyl thymine prepared in accordance with cruickshank et al tetrahedron lett 2 5 681 684 1984 1.