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Grignard and organocuprate reagents catalyze ring opening reactions of 3, 4-disubstituted N-BOC-beta-lactams to yield alpha,gamma-disubstituted beta-amino ketones. NMR analysis of the crude mixtures helps estimate the proportion of products generated in the reaction. Nature of Grignard reagents influences the reaction. The disubstituted ketones help synthesize alpha-amino acids and polyhydroxylated nitrogen-containing products.

Studies reveal that asymmetric 1, 4-addition of higher order silylcuprates to Oppolzer's N-enoylsultams is as diastereofacially selective as carbocupration of beta-silyl-substituted N-enoylsultams. Silylcupration efficiently yields enantiomerically pure beta-silyl carboxylic acid. H NMR spectroscopy yields the diastereomeric ratio for the addition reactions after flash chromatography of the initial reaction mixture.

A stereocontrolled synthetic route to racemic thienamycin precursors and beta-(hydroxymethyl)aspartic acid derivatives involves the formation of cis- and trans-3- 1'-(dimethylphenylsilyl)ethyl -4-alkoxycarbonyl beta-lactams. The beta-lactams result from the condensation of glyoxylic ester imines with acid chlorides (which leads to the cis-form) or with organocopper enolates (which leads to the trans-form), using the dimethylphenylsilyl group as a masked hydroxy function.

Background: The purpose of the Aging-ONDUAL-TASK study is to determine if a supervised dual-task program carried out in long-term nursing homes is able to attenuate frailty in a greater extent than the same multicomponent exercise program alone.Methods: This multicenter randomized controlled trial will include 188 participants who will be randomly allocated to either a multicomponent exercise program or to the same multicomponent program with simultaneous cognitive training (dual-task training). Inclusion criteria are as follows: ≥ 70 years, ≥ 50 on the Barthel Index, ≥ 20 on the Mini Examen Cognoscitivo (MEC-35) who are able to stand up and walk independently for 10 m. Subjects in the multicomponent group will attend a twice-a-week multicomponent exercise program of 1-h duration per session, consisting of strength and balance exercises. Participants in the dual-task group will perform the same multicomponent exercise program with concurrent individually tailored cognitive tasks. Study assessments will be conducted at baseline and at 3 months. The primary outcome measure will be gait speed under dual-task conditions and secondary outcomes will include physical fitness measurements, gait spatiotemporal parameters, cognition and emotional assessments, several frailty scales and objectively measured physical activity.Discussion: The present research will add valuable information to the knowledge around the effects of the dual-task program in long-term nursing home residents, taking altogether physical, cognitive and emotional variables linked to frailty.Trial Registration: Australian and New Zealand Clinical Trials Registry (ANZCTR) with the identifier: ACTRN12618000536268 . Registration date: 11/04/2018. [ABSTRACT FROM AUTHOR]