1. INTRODUCTION Bicyclic oxygen heterocycles resulting from fusion of benzene ring with
5, 6-positions of either 2H-or 4H-pyran ring system are designated as 2H-chromene (2H-1 …

Abstract 2H-Pyran-2-ones are widely present in nature and found as either isolated or in
fused form. Depending on the fusion of benzene ring, pyran can give coumarins …

New racemic dispiranic polyketides, tsavoenones A (1), B (2) and C (3), having a novel 1, 7-
dioxadispiro [4.0. 4.4] tetradecane scaffold were isolated from the foliose lichen Parmotrema …

A series of fluorescent teraryls and quateraryls were prepared from a ketene-S, S-acetal
under mild conditions. These compounds exhibited blue, sky-blue and green color …

A metal-free, ultrasound-assisted approach for the synthesis of highly functionalized 2-
tetralones in high yields is described. The process involves ring transformation of 2H-pyran …

A facile synthesis of highly functionalized spirobutenolides was carried out by a nitroalkane
carbanion-induced ring opening and relactonization via a denitration reaction of 2-oxo-5, 6 …

Scrub typhus (ST) is one of the most neglected tropical diseases, a leading cause of acute
undifferentiated febrile illness in areas of the 'tsutsugamushi triangle', diagnosed frequently …

Newer, simple and efficient synthesis of 2-((5-methoxynaphthalen-1-yl) methyl)-3-methyl-5-
sec-amino-[1, 1′-biphenyl]-4-carbonitrile derivatives using ring transformation strategy. The …

Abstract The synthesis of 4-aryl-2H-pyran-2-ones 7 was accomplished by rearrangement of
6-aryl-2H-pyran-ones 5 with ethyl cyanoacetate 6 in the presence of a base in DMF at room …

Ces travaux de thèse s' inscrivent dans un projet à long terme concernant le développement
de nouvelles réactions de contraction de cycle originales afin d'accéder à des édifices …