Hydroxylated metabolites of loratadine: an example of conformational diastereomers due to atropisomerism

Conformational analysis of cycloheptane, oxacycloheptane, 1,2‐dioxacycloheptane, 1,3‐dioxacycloheptane, and 1,4‐dioxacycloheptane

“…Although a standard OO bond length of 1.480 Å has been suggested for dialkyl peroxides, shorter bonds are observed with electron withdrawing substituents and longer bonds suggest cyclic strain as in 1,2‐dioxacyclobutane and 1,2‐dioxacyclopropane (dioxirane) 1, 2, 8, 9, 63. In our studies of six‐membered ring oxygen heterocycles it was observed that B3LYP/6‐311+G(d,p) predicts OO bonds in the chair conformations of 1,2‐dioxacyclohexane (C 2 ), 1,2,4,5‐tetraoxacyclohexane (C 2h ), and 3,3,6,6‐tetramethyl‐1,2,4,5‐tetraoxacyclohexane (C 2h ) to be 1.457, 1.462, and 1.457 Å, respectively.…”

“…Cycloheptane ( 1 , Fig. 1) and its hetero derivatives (heterocycloheptanes) are important compounds in many areas of science and are found in Alzheimer drugs, anticancer agents, antimalarials 4, 5, natural products 6–10, and polymers. Although cyclohexane and heterocyclohexanes have been studied extensively, there is relatively less information available concerning the conformations, structures, properties, and chemistry of the more flexible cycloheptane 1 and heterocycloheptanes 11–22.…”

A simple, diversity oriented synthesis of highly substituted pyridines

“…The dicyano‐pyridines 10 and 15 were synthesized in high yields by dehydration of the primary amides 8b and 13b , respectively, with phosphorus oxychloride (Schemes and ) [11].…”

Bridgehead modification of trihalocycloheptabenzopyridine lead to a potent farnesyl protein transferase inhibitor with improved oral metabolic stability

“…5 Preliminary studies from phase I and II studies demonstrated SARA-SAR Ò to be well tolerated in patients and efficacy was observed in some of these studies. 6 In an earlier publication by Piwinski et al,7 it was shown that Loratadine Ò , a tricyclic benzacycloheptapyridine closely related to SARASAR Ò , metabolized in rats to give, among other products, the hydroxylated compounds at positions 5 and 6 on the bridgehead (Fig. 2).…”