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Synthesis of tritium labelled precocenes
Author(s) -
Banerji A.,
Goomer N. C.
Publication year - 1981
Publication title -
journal of labelled compounds and radiopharmaceuticals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 47
eISSN - 1099-1344
pISSN - 0362-4803
DOI - 10.1002/jlcr.2580181205
Subject(s) - chemistry , tritium , acetone , lithium aluminium hydride , lithium (medication) , dehydration , aluminum hydride , organic chemistry , radiochemistry , nuclear chemistry , catalysis , medicine , biochemistry , physics , nuclear physics , endocrinology , methoxide
Regiospecific syntheses of tritium labelled precocene I ( 5a ) and precocene II ( 5b ), the antijuvenile hormones, have been accomplished. The syntheses involved condensations between 2‐hydroxyacetophenones ( 1 ) with acetone‐T to give cross condensation products 2 which on cyclodehydration furnished 2,2‐dimethyl‐4‐chromanones‐(2‐ gem dimethyl ‐T) ( 3 ). Reduction of 3 with lithium aluminium hydride gave chroman‐4‐ols (2‐ gem dimethyl ‐T) ( 4 ). Dehydration of 4 furnished 2,2‐dimethyl‐ chromenes‐ (2‐ gem dimethyl ‐T) ( 5 ). Starting with appropriate acetophenones and acetone‐T, precocene I (7‐methoxy‐2,2‐dimethylchromene) and precocene II (6, 7‐dimethoxy‐2, 2‐dimethylchromene) labelled with tritium in the 2‐ gem dimethyl positions, have been synthesised in high chemical as well as radiochemical yields.