Adventures in Atropisomerism: Total Synthesis of a Complex Active Pharmaceutical Ingredient with Two Chirality Axes.

A strategy to prepare compounds with multiple chirality axes, which has led to a concise total synthesis of compound 1A with complete stereocontrol, is reported.

A Claisen approach to 4'-Ed4T.

An efficient, stereoselective synthesis of 4'-Ed4T is demonstrated. The synthesis is highlighted by a regioselective TMSOTf-mediated acetal opening, a Claisen rearrangement to set the key 4'-stereocenter as well as the olefin, and a one-pot nonaflation/elimination to deliver the alkyne moiety. The synthesis proceeds in eight steps from 5-methyluridine and occurs in 37% overall yield.

Process research and development for a tetrazole-based growth hormone secretagogue (GHS) pharmaceutical development candidate.

BMS-317180 (1) is a potent, orally active agonist of the human growth hormone secretagogue (GHS) receptor. This manuscript details the process research and development efforts that enabled the synthesis of the phosphate salt of 1 on a multi-kilogram scale. Key considerations in the development of this process focused on safe execution and the requirement for telescoped synthetic transformations (i.

20-hydroxyeicosatetraenoic acid (20-HETE): structural determinants for renal vasoconstriction.

The effects of natural and synthetic eicosanoids on the diameter of rat interlobular arteries studied in vitro were compared to that of the potent, endogenous vasoconstrictor 20-HETE. Vasoconstrictor activity was optimum for chain lengths of 20-22 carbons with at least one olefin or epoxide between located between C(13)-C(15) and an oxygen substituent at C(20)-C(22). The presence of delta (Zou et al.