Switching the stereochemical outcome of 6-endo-trig cyclizations; Synthesis of 2,6-Cis-6-substituted 4-oxopipecolic acids

A base-mediated 6-endo-trig cyclization of readily accessible enone-derived α-amino acids has been developed for the direct synthesis of novel 2,6-cis-6- substituted-4-oxo-L-pipecolic acids. A range of aliphatic and aryl side chains were tolerated by this mild procedure to give the target compounds in good overall yields. Molecular modeling of the 6-endo-trig cyclization allowed some insight as to how these compounds were formed, with the enolate intermediate generated via an equilibrium process, followed by irreversible tautomerization/neutralization providing the driving force for product formation. Stereoselective reduction and deprotection of the resulting 2,6-cis-6-substituted 4-oxo-L-pipecolic acids to the corresponding 4-hydroxy-L-pipecolic acids was also performed

Correction to: Cluster identification, selection, and description in Cluster randomized crossover trials: the PREP-IT trials

An amendment to this paper has been published and can be accessed via the original article

The influence of time spent in outdoor play on daily and aerobic step count in Costa Rican children

The aim of this study was to examine the influence of time spent in outdoor play on daily physical activity in fifth grade Costa Rican children. Children (N = 190) wore Omron HJ- 720 ITC pedometers for one week to assess their step count and aerobic steps, and completed an Outdoor Play Survey. Results revealed that children who spent 3+ hours in outdoor play per day had higher step counts than those who spent less than an hour per day, p = .018. Children were more active over the weekdays than weekend days, and girls acquired significantly fewer steps then boys (p \u3c .05). These findings suggest outdoor intervention is needed to promote healthy benefits associated with physical activity among children in Costa Rica, particularly for girls and over the weekend