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A New Synthesis of Ciliapterin and Dictyopterin. Ene Reactions of (Alkenylamino)‐nitroso‐pyrimidines
Author(s) -
Zhang FangLi,
Vasella Andrea
Publication year - 2008
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200890255
Subject(s) - chemistry , ene reaction , pyrimidine , nitroso , pteridine , nitroso compounds , reactivity (psychology) , stereochemistry , dihydroxylation , medicinal chemistry , organic chemistry , enzyme , enantioselective synthesis , medicine , alternative medicine , pathology , catalysis
A comparison of the reactivity of (acylamino)‐nitroso‐pyrimidines 1 and the alkenylamino analogue 17 in intramolecular ene reactions showed the considerably lower reactivity of 17 , leading to the pteridine 18 . Pteridin‐7‐one 11 resulting from 1 (R 1 =OBn, R 2 =Me) was transformed into 4‐(benzyloxy)‐6‐[( E )‐prop‐1‐enyl]pteridin‐2‐amine ( 13 ) by O ‐triflation, followed by reduction with LiBHEt 3 , while the 4‐MeO analogue 18 was prepared by spontaneous oxidation of the initial ene product of 17 . The (alkenylamino)‐nitroso‐pyrimidine 17 was synthesized by substitution of the dimethoxy‐nitroso‐pyrimidine 16 with the allylamine 15 . Ciliapterin ( 5 ) and dictyopterin ( 7 ) were synthesized from pteridine 18 by a Sharpless asymmetric dihydroxylation.