Efficient synthesis of enantiopure conduritols by ring-closing metathesis.

Two short synthetic approaches to enantiopure conduritols are described starting from the chiral pool. In both cases, the cyclohexene ring is assembled via ring-closing olefin metathesis. The terminal diene precursers for the metathesis reaction are prepared either from octitols or from tartaric acids. The former route involves a new method for selective bromination of the primary positions in long-chain carbohydrate polyols. Subsequent reductive elimination with zinc then generates the diene. The latter route uses a highly diastereoselective addition of divinylzinc to tartaric dialdehydes for preparation of the dienes.

Impact of antenatal exposure of mice to fenfluramine on cardiac development and long-term growth of the offspring.

The objective of this investigation was to determine, in a placebo-controlled manner, whether antenatal exposure to formulations of fenfluramine and dexfenfluramine impacted cardiac development and long-term growth of exposed mice offspring. One hundred forty-four CD-1 mice were randomized to six treatment groups (n=23 or 25) to obtain, per group, 5 gravids for killing on gestational day (GD) 15 and < or =10 deliveries for assessing growth of the offspring. Either fenfluramine preparation was administered in feed bars in two doses: 1 and 3.2 times the equivalent human daily dosage according to body surface area. The drugs were given from 2 weeks before mating until GD 15. The mice ingested each drug at target values, averaging 10.5+/-0.3 and 31.8+/-1.9 mg/kg/d for fenfluramine and 5.0+/-0.2 and 16.2+/-0.4 mg/kg/d for dexfenfluramine. The drug concentration was about 36% in the fetal brain compared with the adult brain. The maternal and the offspring hearts, including mitral and aortic valves, of fenfluramine-exposed mice were indistinguishable from the placebo-exposed mice. The duration of gestation and the litter size were the same between the treatment groups. The mean body weights, body lengths, and head circumferences and early functional testing did not differ significantly between the fenfluramine or dexfenfluramine-exposed offspring and the placebo-exposed offspring. There were no significant treatment differences in growth measured as body weights to PND 120. Neither fenfluramine formulation, given before conception and during gestation, impacted cardiac development and long-term growth of the mice offspring.